Feeds:
Posts
Comments
Set up for the stop-motion animation activity. You will need a solid tripod, a black-topped table with good lighting, and rulers to mark the edges of the stage area (camera field of view).

Set up for the stop-motion animation activity. You will need a solid tripod, a black-topped table with good lighting, and rulers to mark the edges of the stage area (camera field of view).

As part of the STEM-Arts Alliance program I’ve initiated at Walden School of Liberal Arts, I am always trying to find activities in my science classes that can integrate art, history, and/or technology. At the NSTA national conference in San Antonio in 2013, I attended a session by Dan Ratliffe from the Breck School in Minneapolis on using stop-motion animation techniques to model a chemical reaction, in this case the burning of methane. He showed how to set up a stage, use student groups and manipulatives, and how to show how energy is absorbed (activation energy) to start the reaction and how energy is released. He uses it in his 6th grade science class, but I’ve adapted the lesson for use in higher level science classes such as chemistry or physics or astronomy.

Animation stage (marked with rulers). Since the camera couldn't point straight down, the stage is a trapezoid. On the large sheet of paper is our storyboard/plan.

Animation stage (marked with rulers). Since the camera couldn’t point straight down, the stage is a trapezoid. On the large sheet of paper is our storyboard/plan.

On Jan, 31 this year, I needed to make one of these animations for a demonstration I was doing at the UACTE conference. My chemistry students were studying nuclear chemistry and nuclear reactions at the time, so without any warning to them, I announced we would be making an animation of the nuclear fission of Uranium-235. I had cardstock and permanent markers already in the room, and brought my camera and tripod to class. My small class of students were able to create all the drawings and labels, plan the sequence, and do the photos all in one class period plus a few minutes after school to clean up, so about 80 minutes total. It wasn’t anything too fancy, but it worked. That evening I dropped the images into Apple Final Cut Studio (setting each image to last three frames), then dropped them onto the timeline, expanded them all together so the edge of the stage wouldn’t show, and exported it. I didn’t try to add narration or sound effects, but it did the job. Then I demonstrated the process at the conference the next day.

This lesson meets standards HS-PS1-8 of the Next Generation Science Standards to model nuclear reactions as a core idea in chemistry. I have written it all up as a PDF lesson plan. I’m including the process steps here, but you can download and use the lesson plan here: Stop-Motion_Nuclear_Reaction

Objectives: By the end of the activity, students will be able to:

  1. Create storyboards and sketches showing the stages of a chemical or nuclear process;
  2. Set up a stage and move objects around from frame to frame to demonstrate the process;
  3. Edit and align sequential images in an image editing software package;
  4. Import a series of still images into video editing software and export the sequential images as a continuous animation.

 

An early frame for the animation. A neutron (red bead) approaches an atom of U-235.

An early frame for the animation. A neutron (red bead) approaches an atom of U-235.

Materials for each group:

Regular unlined copy paper (for storyboards)

Cardstock paper (for labels)

Marker pens or colored pencils

Balls of different sizes to represent large uranium atoms, smaller fission products, and

neutrons. You can use poker chips and tiddlywinks instead.

Scissors

Clear tape

A black-topped lab bench or table with a black tablecloth

A digital camera and tripod that can look down on the table without seeing the edges

Meter sticks and smaller metric rulers

Computer with video software

 

The first atom of U-235 splits into Barium and Krypton plus energy and two additional neutrons.

The first atom of U-235 splits into Barium and Krypton plus energy and two additional neutrons.

Step One: Introduction

Introduce this lesson by showing your students some examples of stop-motion animation and discussing how traditional animation was drawn frame by frame on acetate sheets. Explain that they will be creating their own animations in groups.

Review the types of nuclear reactions that are most often learned in a unit on nuclear chemistry, such as the fission of Uranium-235; the fusion of hydrogen; nucleosynthesis inside a star; the conversion of a neutron to a proton, anti-electron neutrino, and beta particle through the weak nuclear force; the beta and alpha decays of various elements; the conservation and conversions of energy and matter in a nuclear reaction; etc. List these reactions on your whiteboard. Assign students to groups of 4 to 5, and have each group pick a different reaction.

 

The three neutrons travel on toward three more U-235 atoms.

The three neutrons travel on toward three more U-235 atoms.

Step Two: Planning the Animation and Creating the Pieces

Divide the students into groups and provide them with the materials they need. For this first period (initial 45 minutes) they will research the relevant reactions, draw out a storyboard or plan for the steps of the process, write a narration script (optional), then create the pieces they need. They can represent atoms or subatomic particles by balls or paper drawings on cardstock. If they use balls, they should create paper labels for each object. Energy can be represented in different ways, such as drawing lightning bolts or gamma rays or bursts of energy.

Give the students encouragement and suggestions as needed, but allow them to use their creativity and have fun with this activity. They may want to bring in their own props. The final storyboards and animations should be scientifically accurate and demonstrate deep knowledge of the reaction they choose as well as be aesthetically pleasing and well designed. They should also create titles and show the reactions as equations. By the end of 45 minutes they should have their plans complete and their pieces, labels, and drawings finished and cut out.

As an option, you may want each group to write up a narration script and record the narration using a microphone. If you do this, then allow for an additional class period. The final animation will have to be carefully timed to match this narration.

 

The three atoms of U-235 split to create new byproducts, more energy, and a total of nine neutrons.

The three atoms of U-235 split to create new byproducts, more energy, and a total of nine neutrons.

Step Three: Filming the Animation Frames

To set up the animation, a camera should be mounted on a tripod or other solid structure and placed so that its field of view encompasses a black lab bench or table topped with a black tablecloth without seeing any edges. To find out the exact area of this “stage,” use meter sticks or other straight edged objects and move them in on all four sides of the camera’s view until you can just barely see them at the edge of the view. If your camera is facing straight down, the stage will be a rectangle, but this is often difficult to achieve without making a special frame or mount for the camera. If it is on a tripod, then it will be looking at the stage at an oblique angle and the stage area will be a trapezoid. Once the stage area is set and the camera is in place, they must not be moved.

To film the frames, have one student assigned to use the camera (and not bump it or move it between frames). The other students will move the pieces. They will want to practice the process, deciding how far to move each piece between frames. A good frame rate for the final video would be 10 images per second. Since digital video plays back at 30 frames per second, this means one image will be three frames long. This means for a 10 second animation, you will need to take 100 photos. If each piece is moved too much between images, the resulting animation will be jerky and too fast. If it is moved slower, the resulting animation will be smoother but you will have to take more photos. The amount of motion between frames should be consistent or the movement will seem to speed up and slow down for no reason. Students should use a ruler to measure the distances to move objects between frames exactly. Objects such as atoms that need to stay in place for several seconds can be taped down with clear tape.

Once they get going, the group can develop a kind of rhythm. They will stand around the stage with the camera operator calling out, “Move. Clear! Move. Clear!” and taking photos as the students clear out, then move their assigned pieces as planned. A student should also be assigned as the Director to ensure the storyboard is followed and object placement is correct from frame to frame. Labels should be used for all parts, such as neutrons, atoms, energy, equations, titles, etc. When an atom is split or atoms fuse, if energy is released, it can be shown appearing and moving outward from its origin or creating a flash. Byproduct particles can then move on to collide with other objects. For example, if you are splitting U-235, then a neutron enters, collides with an atom of U-235, which splits into two products (there are several possibilities, such as Krypton-89 and Barium-144, or Xenon-143 and Strontium-90, etc.) along with two new neutrons and gamma radiation. A chain reaction can be demonstrated going through several steps. They could even show a mushroom cloud at the end.

Special effects can be created, such as blinking objects (having an object appear in one frame, then disappear in the next, and alternate – it will appear to blink or flash in the video). With a little practice you can get the timing right. You can create explosion graphics and add white or colored frames to simulate a flash of energy. If your students know how to use image software to create alpha channels, then separate images can be filmed and added with transparency to the final video as layered animations. In the end, the only important things are to keep the motion smooth and consistent, don’t bump the camera, and don’t get anyone’s hands in the photos.

 

The nine neutrons travel on to split nine atoms of U-235 and release even more energy and more neutrons . . . thus becoming a chain reaction that will result in a nuclear explosion if left unchecked. Labels and equations can be added as the final particles migrate off the stage.

The nine neutrons travel on to split nine atoms of U-235 and release even more energy and more neutrons . . . thus becoming a chain reaction that will result in a nuclear explosion if left unchecked. Labels and equations can be added as the final particles migrate off the stage.

Step Four: Creating the Video

The photos will need to be uploaded to the computer which has the video software. Ideally each group should have a computer capable of doing this; almost any video software including iMovie and MovieMaker will work. There are apps available for iPads or other tablet computers such as iStopMotion. As you import the images, make sure they are numbered sequentially. Most digital cameras will do this automatically.

If there was any bumping of the camera, then the images may need to be aligned or registered using image editing software. Each image can be imported as a separate layer and moved around to align it with the rulers seen along the edges in the bottom layer. This will be a tedious process, so it is far better not to bump the camera in the first place!

If the photos are well aligned, then you can import them directly into your video editing software. Some programs allow you to set the length in frames of each imported image. You would want to set the images to three frames each if your final frame rate is 10 images per second. Once imported, if they are numbered sequentially, all you need to do is select all the images and drag them to your timeline in the video software and they will be in the right order and length.

Since the rulers can be seen along the edges of each image, you will need to enlarge the images. This can be done in two ways. The first is to expand the first image, then apply the same settings to each subsequent image. This is a slow and boring process. It’s much faster to simply export the video as is, then open a new file and import the draft video and place it on the timeline. Then the entire video as a single clip can be expanded to move the rulers off stage, and the final video exported again. You can add special effects (inserting flash frames, titles, additional layers, etc.), add narration and/or music and sound effects, and export the final version.

 

Step Five: Evaluation

Once the videos are done and ready to view, give the students feedback forms that ask them to evaluate the final videos, including their own, on such areas as scientific accuracy, depth of knowledge, technical ability, and aesthetics/design. Leave room for comments. Show the animations to the class, and have them fill out a feedback form for each video, encouraging the students to make positive suggestions. Then collect the forms and tally the results as a final grade for the assignment. You will want to evaluate the videos yourself as well and give more detailed feedback on how they can improve. You could also create a master video by piecing all the group projects into one video, then upload the whole thing to YouTube so other schools/classes can view it.

 

Notes on this Lesson:

This idea could also be used to model any process or natural cycle, such as chemical equilibrium, phase changes, types of reactions, conservation of matter and energy, kinetics, pH titrations, and thermodynamics in chemistry and the rock cycle, the water cycle, the carbon cycle, stellar evolution, plate tectonics, etc. in other sciences. I would enjoy hearing your ideas. Please let me know how you are using this activity by e-mailing me at: elementsunearthed@gmail.com.

Element ornaments made by chemistry students at Walden School of Liberal Arts

Element ornaments made by chemistry students at Walden School of Liberal Arts

Leading up to Winter Break, we were learning about the elements and their properties in my chemistry class at Walden School of Liberal Arts. It seemed a good time to have my students pick an element to research and find out more about, but I didn’t want to have them do the “standard research paper.” I also wanted this project to incorporate some type of art as we are continuing on with the STEM-Arts Alliance program.

I decided to try out an activity that one of our former teachers at Walden, Matt Ellsworth, used last year: have the students pick an element and create an “ornament” that reflects something about the element, such as an outstanding property, a commercial use, its form as a mineral, etc. He also had them write physical values of the element on the ornaments, such as electron configuration, symbol, atomic number, atomic weight, and so forth.

My chemistry class is small, so not a lot of ornaments were made, but the results were overall quite good. As you can see from the photo, the ornaments incorporate some interesting designs and 3D effects. For example, the ornament of the space shuttle is for beryllium because that element was used in the brake linings and window frames of the space shuttle. Beryllium is mined principally in western Utah in the Spor Mountain range. An even more characteristic use would be to design the ornament to look like the James Webb Space Telescope, since its primary mirror is made from Utah beryllium.

A synthetic bismuth crystal. Notice the play of colors across its surface.

A synthetic bismuth crystal. Notice the play of colors across its surface.

The ornament on bismuth is very well done – it shows the structure and iridescent coloring of a single bismuth crystal. I’ve photographed bismuth crystals very much like it on display in Theo Grey’s office in Urbana-Champagne, Illinois. He is a noted collector of the chemical elements, the author of a photographic table of the elements, and creator of the best-selling iPad periodic table app. He was very accommodating to allow me to interview him in his office (sitting at his hand made wooden periodic table conference table) on my way home from Philadelphia in 2009.

This makes a great high-interest activity to do when students start to get restless before Winter Break. They can be quite creative in how they design and build their ornaments, and each year you can save the best ones to display. We simply used unfolded paper clips to hang them in class, and construction paper, scissors, glue, and tape to put them together.

Another view of student ornaments.

Another view of student ornaments.

You could also combine this with making ornaments from crystallized supersaturated salt solutions, such as copper (II) sulfate or Epsom salts (magnesium sulfate). Just look up the solubility of the salts and make a saturated solution, then bend some pipe cleaners in desired shapes representing the various holidays of Winter Break, such as the Star of David, or representing chemistry shapes (a Florence flask, a test tube, a beaker, etc.). Make a hook and hang the shape from a pencil in the solution, making sure not to touch the sides or other ornaments. After a few days, after crystals have formed, the ornaments can be removed and dried. We weren’t able to get to this activity, which I first learned about from a Flinn Scientific lab. But I have the materials and will try it next year.

Another idea would be to use mineral samples as ornaments – with thin wire you can create a cage for a small sample of quartz or calcite or some other crystalline mineral to hang as an ornament. With some good epoxy glue you could attach a hook directly to a crystal. Of course, such mineral samples could also be used as jewelry (necklaces, earrings, etc.). A final idea could be to use some unvarnished copper sheeting or brass sheeting to cut ornament shapes, then use chemicals to create a patina on their surface. For example, if you leave copper and brass in a sealed container with ammonia and salt, they will turn nice blue color. If left in a container with vinegar and salt (or evan salt and vinegar potato chips crumbled up with a little extra vinegar added) the copper and brass will turn a nice green color as copper acetate forms.

Shapes cut from sheets of copper and brass, treated with vinegar and salt (green patina) and ammonia and salt (blue patina).

Shapes cut from sheets of copper and brass, treated with vinegar and salt (green patina) and ammonia and salt (blue patina).

Paintings made with homemade pigments for my Intersession Science and Art class

Paintings made with homemade pigments for my Intersession Science and Art class

As a follow up to our lab for making iron-gall ink, I wanted to find recipes online for turning a standard high school chemical inventory into paint pigments for watercolors, pastels, or oil paints. I found some websites that use natural ingredients such as berry juice or even walnut shells, but not much on how traditional paint colors were made or how to make them today so they are colorfast and lightfast.

Lemon yellow pigment made from a double replacement reaction of barium nitrate and potassium chromate.

Lemon yellow pigment made from a double replacement reaction of barium nitrate and potassium chromate.

To make an ideal pigment, it must have several properties. It must be suspendable in some sort of medium, such as water or linseed oil. This means it forms fairly large particles that are opaque to light yet small enough to not settle out of solution immediately. Once on paper or canvas they should resist re-dissolving (waterproof) in the case of watercolors but be re-workable in oil paints. Pigments must stay the same color under a wide range of circumstances, including minor changes in pH or humidity or under exposure to light.

The Villa of Mysteries in Pompeii. The red background color is vermilion, or mercury sulfide made from cinnabar. According to Pliny the Elder, the painters made a nice side profit by frequently washing their brushes and taking home the wash water.

The Villa of Mysteries in Pompeii. The red background color is vermilion, or mercury sulfide made from cinnabar. According to Pliny the Elder, the painters made a nice side profit by frequently washing their brushes and taking home the wash water.

Many paint pigments were originally made from colorful rocks or minerals, such as lapis lazuli, aquamarine, charcoal, orpiment, or cinnabar. Some of these minerals, such as cinnabar (mercury (II) sulfide) are toxic. Most of the red pigments tend to be this way, or else aren’t a very bright shade of red. Yes, iron oxide (rust) makes a reddish brown and madder root makes a dull burgundy, but only cinnabar (also known as vermilion or Chinese red, which is a bright orange red) or lead oxides (known as minium) could produce a good red until the Spanish Conquest of the Americas.

Chinese red lacquerware box colored with Chinese red, or cinnabar.

Chinese red lacquerware box colored with Chinese red, or cinnabar.

When Cortez conquered Mexico, he found an abundance of cloth dyed a bright red color and on investigation found that the dye was produced from a ground up insect called cochineal. It produced a range of bright reds from magenta through red-orange, depending on how it was treated. He brought samples of the cloth and the bug (along with samples of chocolate, but that’s another story) back to Spain with him. The insect grows on a particular species of prickly pear cactus in Central and South America, and the Spanish eventually found it could grow and prosper in some parts of southern Spain and on the Canary Islands. The dye it produces is called carmine. It is the red of a cardinal’s robes and the red of the British Redcoats. It is still used today, including in various types of red or pink-dyed foods, including strawberry milkshakes. In the food industry, it is known as Red Dye # 4.

Cochineal insects living on large cacti. The female insects are sessile, attaching themselves permanently to the cactus and extruding a waxy coating to prevent dehydration. The carminic acid helps to ward off predators.

Cochineal insects living on large cacti. The female insects are sessile, attaching themselves permanently to the cactus and extruding a waxy coating to prevent dehydration. The carminic acid helps to ward off predators.

The types of reds used for painting now are cadmium red (which is rather expensive to make) and alizarin crimson, a synthetic pigment made from coal tar derivatives. You can also get a pink color by using a hydrated form of cobalt chloride as a pigment, but it turns bright blue as it dries out.

Grinding dried cochineal insects to make carmine pigment. This dye is also used in foods. Yes, you are eating bug juice.

Grinding dried cochineal insects to make carmine pigment. This dye is also used in foods. Yes, you are eating bug juice.

After searching all this out, I finally came across a website that provided information on the history and production of various pigments. It is called Pigments Through the Ages and has a URL of: http://www.webexhibits.org/pigments/. It shows all the various colors made, gives the history and traditional methods for producing them, as well as modern equivalents. I determined to try these out in my chemistry and Intersession classes. We did some experimentation and here are the recipes we developed:

Pigment recipes

Once we got a viable pigment, we added a few drops of gum Arabic as a binder and to thicken the pigment. Then we tried it out by sketching and painting illustrations. My chemistry class had to paint something related to the history of chemistry or their own chemistry presentation topic.

Chemistry student Evan makes synthetic yellow ochre pigment.

Chemistry student Evan makes synthetic yellow ochre pigment.

Please feel free to experiment, adapt, and test these formulas. From our experiments we had some interesting results. The Cobalt blue recipe was a light purple/pink in solution (the hydrated cobalt chlorides) but dried a bright cyan blue color. This happened every time we made it in class, yet one student who wanted to test these pigments as a science fair project made her own cobalt blue which turned out staying a medium blue as the recipe said it should. I’m not sure what she did differently. When we made the cobalt purple, the student wanted to thicken the resulting solution by boiling off some of the water. This produced a bright pink pigment that was colorfast and was very useful combined with lemon yellow to make a flesh tone.

Making cobalt blue pigment.

Making cobalt blue pigment.

The lemon yellow and Prussian blue formulas are infallible. The yellow ochre recipe was interesting. It starts with the same cobalt chloride as two other pigments, but uses glacial acetic acid to convert it to yellow. It works to make a powder and then hydrate it once the process is done, producing a pigment that is a dull yellowish gray dry but makes an intense slightly grayish yellow when dissolved in water. The carbon black (India black) was easily made from finely ground charcoal, although I would use a charcoal without self-lighting fluid. It makes an oil slick on the pigment. You could probably use soot even more advantageously as it is already finely divided. Just build a small campfire and put a piece of metal over the flames to collect soot, then scrape it off for a pigment.

Making pigments in the lab at Walden School

Making pigments in the lab at Walden School

The colors we had trouble with were browns and reds. I have not tried making a pigment from walnut shells, although I have collected some for the purpose. I did try to make brown using a piece of yellow ochre mineral (iron sulfide and oxide) I had, but the powdered ochre would not mix with water and rubbed off the paper even when I tried using some gum Arabic to bind it.

Beginning to paint the background washes using cobalt blue (which looks pink when wet) and prussian blue.

Beginning to paint the background washes using cobalt blue (which looks pink when wet) and prussian blue.

As explained above, red is a problem. I didn’t want to make red using lead or mercury compounds (minium or vermilion) and I couldn’t afford the cadmium, so the last result was to use cochineal, which I ordered from the Dharma Trading Company. Our first attempt was only partially successful. We ground up the insect bodies in a mortar and pestle and a red fluid came out, mostly carminic acid. We tried using it directly as a pigment, but the paint turned black with exposure to air. We then tried adding natural chalk (calcium carbonate) to make a lake, and that started as an opaque burgundy but turned black within a few minutes. Finally, I tried using alum powder (aluminum hydrogen phosphate) as a mordant and it made a nice burgundy color that was permanent.

Adding green robes made from a mixture of lemon yellow with cobalt blue and yellow ochre with Prussian blue.

Adding green robes made from a mixture of lemon yellow with cobalt blue and yellow ochre with Prussian blue.

Further research into cochineal told me that the best way to use cochineal to make carmine pigment is to crush the dried bus in a mortar and pestle, then filter the solid parts out by running the bug juice through filter paper or cheesecloth. Then add alum powder to stabilize the deep burgundy color. By adding a little vinegar, the color can turn a bright transparent red to reddish orange that will stain and dye cloth and work well for a watercolor pigment. I will try adding some chalk to it at this point to make the pigment opaque for pastels or paint.

Flesh tones (lemon yellow with cobalt pink) and gray beard (carbon black).

Flesh tones (lemon yellow with cobalt pink) and gray beard (carbon black).

As for the brown colors, even to this day most browns come from a clay which is dug out of deposits near the towns of Sienna and Umbria in Italy, then ground fine and used as a pigment. Sometimes they are heated or “burnt” to darken the color. This produces the colors raw and burnt sienna and burnt umber. I can’t exactly take a trip to Italy just to dig up dirt, so I’m working on my own browns out of walnut shells and other organic and mineral sources. I’m a bit stumped on how to grind up the walnut shells to get a fine powder.

The finished Democritus with pen and ink details. It was painted entirely with homemade pigments and inks.

The finished Democritus with pen and ink details. It was painted entirely with homemade pigments and inks.

I’ve included some of the paintings we’ve done. I did the one on Democritus, but others were done by students. I added details at the end with iron-gall ink and Prussian blue ink and a Speedball drawing pen. I also have a piece of watercolor paper that I’ve been using to paint and test swatches of our homemade paints, and you can see we’ve had some interesting results. We can now create about any hue, shade, or tint we need.

Paper of color swatches, used to try out variations and mixtures of pigments. The stabilized carmine is the deep burgundy swatches. The bright cyan is cobalt blue.

Paper of color swatches, used to try out variations and mixtures of pigments. The stabilized carmine is the deep burgundy swatches. The bright cyan is cobalt blue.

This has been a fun and informative exercise in inquiry and experimentation. We’ve seen most of the types of chemical reactions, have seen a variety of physical and chemical changes, and have even practiced some stoichiometry as we work on the finding the best ratios of reactants for our pigments.

Sebastian painting Greek armor using Prussian blue and cobalt blue with carbon black pigment he made.

Sebastian painting Greek armor using Prussian blue and cobalt blue with carbon black pigment he made.

Painting of stained glass windows by Nicole.

Painting of stained glass windows by Nicole.

A painting of fireworks in progress.

A painting of fireworks in progress.

Visualizing electronegativity of the elements in 3D

Visualizing electronegativity of the elements in 3D

While teaching the history and patterns of the periodic table of the elements to my chemistry students, I wanted them to get a better feel for the concept of periodicity – that some elemental properties repeat periodically as you increase atomic numbers.

Melting points of the elements visualized in 3D

Melting points of the elements visualized in 3D

For example, at the left of each period (row) is an element that is a soft metal that will react with water to produce a strong base. As a family they are called the alkali metals, and consist of lithium, sodium, potassium, rubidium, cesium, and francium. We now know they have a similar electron configuration, with a single electron in an s-type orbital. This electron is easily ionized away and accounts for the alkali metals’ high reactivity. Other families of elements (usually found in columns in the table) include the noble gases, the halogens, and the royal metals (copper, silver, and gold). It was the relationships of similar properties that led Mendelyev (and de Chancourtois, Newlands, Oddling, and Meyer) to develop the periodic table in the first place.

Melting points with a golden texture

Melting points with a golden texture

In an effort to visualize these patterns more clearly, I have devised a technique for taking the numerical values of a property, such as electronegativity, atomic radius, or melting point and turning them into three-dimensional models.

Chart for recording the numerical values of a periodic property

Chart for recording the numerical values of a periodic property

I start with a chart that is divided into squares in the shape of the periodic table, with white squares representing elements and black squares the spaces between and around the sections of the table (you can download this diagram here).

Periodic Properties Chart: 3D periodic properties table

Pairs of students look up one of the periodic properties, then write the numbers down for each element on the chart.

In a text editing program such as Text Edit or Microsoft Word, my students then type in the numbers for each row of the chart, separating them by commas and hitting return or enter to make the next row. For the black squares, they type in a zero. They have to be careful not to leave any element or blank square out. They will have 12 rows of 20 numbers each.

Electronegativity values typed in as comma-separated rows. Blank spaces on the chart are given zeros. The final grid is 12 rows of 20 values each.

Electronegativity values typed in as comma-separated rows. Blank spaces on the chart are given zeros. The final grid is 12 rows of 20 values each.

Once the comma-separated rows of numbers are done and checked, the students save the array as a raw text file (.txt) so that all formatting is erased. They then load the file up into a program called Image J. This program is freeware developed by the National Institute of Health and is very useful for analyzing images. To load in the number array .txt file, students need to go to the file menu and choose “File-Import-Text Image” and select their .txt file. This will create a grayscale image based on the .txt values: the lowest values (the zeros around the edges of the periodic table) are black and the highest value is made white. It will be a small image since the entire array is 20 by 12 pixels. You can save the image created or zoom in on it as close as it will with Command-+ and save a screen shot of it.

Importing the .txt file as a Text Image into Image J software

Importing the .txt file as a Text Image into Image J software

The original grayscale heightmap is only 20 x 12 pixels. You will need to zoom in and save a screen shot of the image.

The original grayscale heightmap is only 20 x 12 pixels. You will need to zoom in and save a screen shot of the image.

In Adobe Photoshop or GIMP, students load in the screen shot and cut it so only the grayscale area remains, then increase the resolution. You will need to blur it slightly (2-3 pixel Gaussian blur) to get rid of artifacts around the edges of the squares. Then make the canvas square by adding a black background using the “Image-Canvas Size” feature in Photoshop. You can do a similar function in GIMP. Save it as an RGB or 8-bit grayscale PSD or PNG file. This prevents the grayscale heightmap from getting distorted in the 3-D terrain editor.

The grayscale heightmap in Image J after zooming in.

The grayscale heightmap in Image J after zooming in.

Now open up your favorite 3-D modeling software. I use Daz3D Bryce because it makes excellent terrains. Most other 3-D software can do terrains out of grayscale heightmaps. Some free or low cost options are Blender and Autodesk Maya (you can find a free PLE version of it). You will then need to load in the square grayscale file you just made using the “Load” buttons in the Picture tab of the Terrain Editor, smooth it, and put a texture on it.

Electronegativity heightmap after adding black edges to make it a square. This avoids distortion in the 3D modeler.

Electronegativity heightmap after adding black edges to make it a square. This avoids distortion in the 3D modeler.

At this point you have a 3-D terrain showing the strength of a periodic property for each element. I am including several examples here. The models can be animated or have a camera fly around it. You can add lights and render out images, then put together a class powerpoint using all the student’s images to demonstrate periodicity and the Periodic Law.

The Terrain Editor in Daz3D Bryce. The model may need additional smoothing to round off artifacts.

The Terrain Editor in Daz3D Bryce. The model may need additional smoothing to round off artifacts.

I’ve also put together a video that describes the history of the periodic table as narrated by Dr. Eric Scerri of UCLA. You can find it on the video page of this blog.

Electronegativity model in Daz3D Bryce. An altitude sensitive texture has been applied.

Electronegativity model in Daz3D Bryce. An altitude sensitive texture has been applied.

Give it this activity a try and let me know how it turns out. I’d love to see examples of what your students come up with.

Electronegativity model in Daz3D Carrara with a little mood lighting

Electronegativity model in Daz3D Carrara with a little mood lighting

Self portrait of Leonardo da VInci

Self portrait of Leonardo da VInci

Ever wonder where ink comes from, how it was invented and how it is made? I do. Most of the ink we use today for printing newspapers or drawing is called “India” ink (although it was invented in China). It uses carbon black, or soot, for the pigment. But before this ink formula reached Europe, artists and scientists used a type of ink based on iron known as iron-gall ink.

Original drawing by Leonardo da Vinci using iron-gall ink

Original drawing by Leonardo da Vinci using iron-gall ink

In July, 1984, I had the opportunity to travel to Europe with my family. Among many works of Renaissance art, I saw a display of original drawings by Leonardo da Vinci in Florence. There were plans of statues he was commissioned to cast, sketches of human anatomy, and designs for fantastic devices. One thing that caught my eye was his artistic ability; how well he could draw directly using pen and ink. I remember wondering where he got his ink from, which had turned brown with age. Now I know the answer, and I’ve turned it into one of my favorite activities in chemistry.

Alchemical manuscript by Sir Isaac Newton, at the Chemical Heritage Foundation

Alchemical manuscript by Sir Isaac Newton, at the Chemical Heritage Foundation

Iron-gall ink was used for about 1400 years and only lost favor in the mid 1800s when India ink replaced it (because it was cheaper and easier to make and produced a more consistent, longer lasting black). But there’s something to be said for the artistic variety and richness of the shades of iron-gall ink and how it has oxidized with time. The manuscript shown here was written by Sir Isaac Newton with his own homemade ink. It is one page of 24 in the possession of the Chemical Heritage Foundation in Philadelphia and is a series of notes he made on his alchemical experiments (yes, Isaac Newton was an alchemist; in fact, he wrote far more pages on alchemy than he ever did on physics).

Isaac Newton's recipe for iron-gall ink

Isaac Newton’s recipe for iron-gall ink

Newton also left behind his own recipe for ink, as seen here. He started out by collecting galls off of oak trees. These galls are formed when a species of wasp lays an egg in an oak bud, which causes the oak to form a rounded ball or gall around the developing wasp larvae. As Newton’s recipe shows, he soaked the galls in strong ale or beer for a month along with solid gum Arabic. The rotting oak galls would produce tannic acid. The gum Arabic, which comes from the gum of acacia bushes in northern Africa, is used here as a binder to help the ink stick to the paper and keep the pigment in suspension, as well as make the ink have a better flow and consistency. Newton would then mix the tannic acid/gum solution with copperas. This is a chemical with a greenish-blue color that was mistakenly thought to contain copper (hence the name) but is really iron (II) sulfate. The mixture of the iron (II) ions with the tannic acid produced a rich dark brown-black suspension ideal as an ink pigment.

Chemistry students making ink

Chemistry students making ink

The question is how to make similar ink using modern equivalents. I’m not about to soak oak galls in ale for weeks; as it turns out, tannic acid is readily available from strong tea. The iron (II) ions can be produced from steel wool by boiling it in vinegar, filtering the solution through wet filter paper, then adding a small amount of 3% hydrogen peroxide. The trick is to not oxidize the iron too much, or you’ll get too much rust (iron (III) oxide) and your ink will be too brown. Getting a nice black color with just a hint of brown is ideal. If the ink is too thin, then it can be left out to evaporate and make it more viscous. A few drops of gum Arabic are added at the end. You can buy gum Arabic in most craft or art supply stores. If you add too much, the ink will be too glossy when it dries. I originally came across this procedure in ChemMatters magazine (“An Iron-Clad Recipe for Ancient Ink” ChemMatters, October, 2001) and have tinkered with it over the years.

Chemistry students drawing illustrations with their own homemade ink

Chemistry students drawing illustrations with their own homemade ink

So what is the ideal recipe to make the darkest ink? That’s the inquiry part of this lab. I have the students experiment with different formulations to see what the best ratios of steel wool, vinegar, hydrogen peroxide, and tea would be. They also change the time that the steel wool/vinegar mixture is allowed to boil. They begin by learning the old recipe using oak galls, then learn the modern equivalents. From that, they identify variables to test. These factors (or ingredients or procedures) can be listed on the board and divided into comparison groups. Small groups of 2-3 students are assigned to each possibility, such as one group testing the amount of steel wool and its gauge, another testing the strength and amount of the vinegar (kitchen strength or glacial acetic acid) and how long to cook it, another group can test the hydrogen peroxide amount, and another the strength and amount of the tea to add. All of these results can be compiled and compared to create the ideal recipe for making the darkest ink.

Using a traditional drawing pen with homemade ink

Using a traditional drawing pen with homemade ink

The procedure outlined in the ChemMatters article calls for students to boil 200 mL of water, then soak two tea bags in it for five minutes. Meanwhile, a steel wool pad is placed in a beaker with 100 mL of vinegar and boiled for seven minutes. The solution is filtered and cooled to room temperature, then 1 mL of 3% hydrogen peroxide is added. The grayish solution turns a reddish brown as the some of the iron (II) is converted to iron (III) ions (during our Intersession class, I had students use 10 mL of the hydrogen peroxide by mistake and their ink turned too brown). The iron solution and the tea are both added to small cups or vials in equal amounts and stirred together. A few drops of gum Arabic are added. My experience using this recipe produced rather anemic gray ink. As you can see from the illustration of Cai Lun (the inventor of paper) by Evan, with some experimentation you can achieve a very nice dark ink which compares favorably with India ink.

Cai Lun, the inventor of paper. Notice how rich and dark the ink is.

Cai Lun, the inventor of paper. Notice how rich and dark the ink is.

Of course, what my students have done deliberately in one class period took people during the Middle Ages centuries of trial and error to develop, and even by Newton’s time, everyone still had their own recipe. As you can see from the manuscript page, his was a good formula and made dark brown-black ink that has held up well for almost 400 years.

Zach practices daring Elvish calligraphy using homemade ink

Zach practices daring Elvish calligraphy using homemade ink

Once my students create good ink, they go farther and use traditional drawing pens to create illustrations related to the history of chemistry. They pick a material to research, such as glass or steel or armor or stained glass or paper, write up its history and manufacturing, and create their own illustrations with the iron-gall ink. I am showing some of these in this blog. We’ve tried different formulas. In the Intersession Science and Art class I taught in March, we cooked the steel wool for too long in the vinegar and got too much iron (III) ions, or added too much strong tea. The result was sepia colored ink instead of dark black, as shown in the ladybug drawing.

Illustration of armor by Sebastian using iron-gall ink

Illustration of armor by Sebastian using iron-gall ink

Try it out for yourselves! Make sure to use uncoated steel wool. You can get it easily at a hardware store. The other chemicals are household strength and readily found, except for the gum Arabic. Most art supply stores do have bottles of this. It is a bit pricey but a little bit is all that is needed. Two bottles should be enough for a class of 30 students. You will also need some bottles or phials to store the ink (it will last a long time and can be reconstituted with water if it dries out), drawing pens and Bristol board illustration paper, which will be the largest expense of your lab.

Illustrations from my Intersession class where the iron was overly oxidized and turned a sepia color.

Illustrations from my Intersession class where the iron was overly oxidized and turned a sepia color.

As an initial demonstration and “hook”, I use a traditional quill pen and some parchment paper to show how it used to be done. I also demonstrate writing Chinese characters (tsz) using ink sticks, inkwells, traditional maubi (drawing brushes), and rice paper. I’m not very good at drawing tsz, but at least I can show how to hold a maubi and use ink sticks (which are not iron-gall ink – they are “India” ink based on carbon black bound together in stick form, then rubbed with water in an ink well). The “love” character shown was drawn by Miyuki, a Japanese exchange student, on parchment.

Illustration of plate glass making by Nicole

Illustration of plate glass making by Nicole

Drawing of Aristotle using iron-gall ink. I did this as a demonstration project for the chemistry students.

Drawing of Aristotle using iron-gall ink. I did this as a demonstration project for the chemistry students.

Illustration of Chinese fireworks by Richard, made with iron-gall ink

Illustration of Chinese fireworks by Richard, made with iron-gall ink

Alec's Anime drawing. Behind it are pigments we made for watercolors. Stay tuned for that post!

Alec’s Anime drawing. Behind it are pigments we made for watercolors. Stay tuned for that post!

Examples of marbled paper made with dilute oil paints floated on water.

Examples of marbled paper made with dilute oil paints floated on water.

As part of the STEM-Arts Alliance project I’ve undertaken at Walden School of Liberal Arts, I have been trying out different ways to integrate art and history into STEM subjects, such as teaching about the history of chemistry and the science behind the fine arts.

Making marbled paper

Making marbled paper

I was sent a lesson activity from Flinn Scientific a year ago on how to make marbled paper, the fancy designed paper you see on the end pages of nicely bound books. The activity seemed fun and easy to do, so I saved it. Now, as part of our project, I’ve dusted it off and tried it out twice in this school year. The first time was at Timp Lodge as a second activity to do while making tie-dye shirts (see my last post). The second time was part of a Science and Art class I did for our Intersession period, which is a two-week specialty course we do between third and fourth terms in March.

Laying paper onto the oil paint layer.

Laying paper onto the oil paint layer.

To do this, you need to buy some disposable trays such as aluminum foil pans or plastic containers. They should be a little larger than the intended size of your paper. You will also need to buy a pad of sketching paper (it needs to be nicer and thicker than copy paper). For colors, you will need to buy a set of cheap oil paints (not acrylic) in various colors, and a large container of mineral spirits to dilute the oil paints. Finally, you will need some small plastic phials or dropper bottles to store the paints in, paper towels, and some disposable eyedroppers.

Walden students making marbled paper at Timp Lodge

Walden students making marbled paper at Timp Lodge

To do the paper, pour about an inch or two of water into the foil pans. Take the oil paints and squeeze out enough paint to fill the phial ¼ full, then add mineral spirits to make it ¾ full. Put on the lid and shake thoroughly. Make sure the paint is completely mixed. Take various paints and drop them onto the water; the oil-based paints are immiscible with the water and will spread out on a layer on top of the water. You can swirl the colors around or not to your taste. Keep adding different colors until you get a nice effect. Then take a piece of the sketching paper and fold it along one edge to make a handle and carefully lay the paper down on the oil layer, making sure not to submerge the paper into the water as you roll it across the top. The oil layer should transfer to the paper. Carefully lift the paper straight up and quickly place it face up on paper towels to dry. Once dry, you can photograph them in good light or scan them into a computer.

Set up to make marbled paper during my Intersession Science and Art class.

Set up to make marbled paper during my Intersession Science and Art class.

Natural fractal patterns created when the oil/mineral spirits separated from the water layer.

Natural fractal patterns created when the oil/mineral spirits separated from the water layer.

This project worked well at Timp Lodge and we made some good examples, although it is very messy. Students should wear aprons and gloves to do this. When we did this activity during Intersession class, we tried using the same paints several times as I had lots of paper left; you can lift out several prints from the same drops, each one getting lighter. At the end of class, a small amount of paint was still floating on top of the water. It had been sitting still for several minutes as the water stopped circulating. The paint separated into strange filamental structures that had formed into fractal patterns. So I lifted a few more prints, as seen here. Now I can scan them and use them for various multimedia projects and for examples of fractals in math classes. I didn’t anticipate that this activity had a math tie in, but there it is!

Marbled paper made during the Intersession class.

Marbled paper made during the Intersession class.

I still have enough paints and paper left to do this activity one more time, perhaps at the elementary school or at our back-to-school Science Showcase night, which will be on April 24. I think the elementary students will enjoy this very much, as did my high school students. I would recommend this as a science and art project for grades 2-12. You can talk about immiscibility, how oils and water don’t mix, and even demonstrate how detergents work. You can also let it sit and teach about fractal math patterns in nature.

Purple marble patterns, lifted from the same paint layer.

Purple marble patterns, lifted from the same paint layer.

Walden School students at TImp Lodge near Sundance.

Walden School students at TImp Lodge near Sundance.

Each year in September we take all the students of Walden School of Liberal Arts up to Timp Lodge, a large cabin above Sundance Ski Resort owned and rented out by Brigham Young University. We rent it for a week and have the different grade levels take turns using it, with the high school using it for three days and two nights. We do this so that students can bond with teachers outside the regular classroom. By breaking up students in various workshops, we also hope to develop friendships between all the students and prevent cliques from forming. We do a variety of activities such as a 2-mile hike to Stewart Falls, workshops for the elementary students, a talent show, and a dance.

Walden School students inside Timp Lodge near Sundance.

Walden School students inside Timp Lodge near Sundance.

During our first day there, each teacher puts together a workshop that is both fun and educational. I had proposed to make Shrinky Dinks using the process I’d learned at the ASM materials science camp this summer, but not enough students signed up for it (I guess I need to come up with a better name . . .). One of our new part-time teachers, Austin, was trying to brainstorm some workshop ideas and I helped out, since he didn’t know what kinds of things would work. We came up with the idea of doing tie-dyed shirts. He had 30 students sign up, so I agreed to help out. Now why didn’t I think of that in the first place?

Wild turkeys at Timp Lodge near Sundance. And I'm not talking about students, either.

Wild turkeys at Timp Lodge near Sundance. And I’m not talking about students, either.

Since not all of the 30 could get around the tables and use the dye bottles at the same time, I came up with an additional idea to make marbled paper. I’ll describe this in my next post. But this time, lets talk tie-dye.

Hiking to Stewart Falls.

Hiking to Stewart Falls.

Austin purchased an assortment of standard Ritz dye colors and some plastic squirt bottles (such as used for catsup or mustard). We had the students bring their own shirts or other clothing items (some did socks, and one even did underwear), but we purchased extras for those who couldn’t bring their own. We also brought tubs and buckets for mixing the dye, plastic disposable tablecloths, large Ziploc bags, rubber bands, and washing soda as a mordant.

Squirt bottles full of fabric dye. We used yellow, orange, carmine, purple, blue, and cyan.

Squirt bottles full of fabric dye. We used yellow, orange, carmine, purple, blue, and cyan.

A mordant is a chemical that forms a coordination complex with the dye molecule so that it can attach permanently to the fabric substrate, such as wool or cotton fibers. As for any pigment, for the color to last, it must be insoluble in water, yet the dye itself must be soluble in water when first mixed. The mordant forms a “lake” (from the old Latin “lac” from which the word shellac is also derived) that makes the dye insoluble and permanent. The mordant is usually a metal ion salt that forms a base in solution, such as washing soda (sodium carbonate). Other common mordants used historically include urea, tannic acid, aluminum salts such as alum (aluminum phosphate), and even salt (sodium chloride). I would like to do this in a more controlled setting sometime to test the effectiveness of different types of mordants.

Method for making a bulls-eye pattern. The center is pulled up while the shirt is twisted slightly, then bound in sections by rubber bands and dyed.

Method for making a bulls-eye pattern. The center is pulled up while the shirt is twisted slightly, then bound in sections by rubber bands and dyed.

Our procedure was to mix the washing soda into a bucket of water and soak the T-shirts in it for several minutes. We then spread them out on the plastic tablecloths and folded them to produce one of several patterns. For example, you can make a spiral design by taking the center point and pinching the cloth, then twisting the whole shirt into a spiral and tying it together with rubber bands around the outside and across the center. The dyes are then squirted onto the rolled up shirt to form wedges of color, overlapping them to make gradients. We discovered that you get more color if you really saturate the dye in the wedges, going over them several times and even squirting some in between the cracks and ridges so that color gets down deep and leaves less white.

Ziploc bags full of dyed T-shirts. The dye was allowed to set before air drying.

Ziploc bags full of dyed T-shirts. The dye was allowed to set before air drying.

To make bulls-eyes, choose the center and pull it up while twisting to make a long rope, then attach rubber bands at intervals to hold the cloth together. Squirt different colors of dye between the rubber bands. Where the rubber bands are pinching the cloth together, less dye will penetrate and will leave white rings separating the bands of color.

Drying T-shirts at Timp Lodge.

Drying T-shirts at Timp Lodge.

To make tiger stripes, lay out the T-shirt face up, then drag your finger from one shoulder diagonally down to the opposite corner, creating a pleated fold that is then held together by rubber bands. Bands of dye color are squirted along it. To make a plaid pattern, take the tiger striped pattern and make a second set of accordion-style pleats.

Plaid, spots, and spiral patterns.

Plaid, spots, and spiral patterns.

We had enough T-shirts that I tried several different patterns to see which were best. I liked all the results, especially the tiger stripes. I think I would create a gradient of colors (say yellow through orange to red) across an unfolded shirt, then fold it and make a second set of colors (blues and greens). That way, interesting color combinations would result and there wouldn’t be any undyed white areas. Or I could do two different patterns on each shirt, letting them dry in between. I will have to do more experimentation.

Tie-dyed shirts showing different patterns.

Tie-dyed shirts showing different patterns.

After applying the dye, the students sealed the shirts in Ziploc bags for several hours to allow the dye to set, then gently washed the soda out. They then let the shirts dry completely in the sun. I told them the color would be fast (permanent) if they heat set it by running the shirt through a drier before washing it. It remains to be seen just how color fast our T-shirts are. The ones I’ve made have held up pretty well.

T-shirts drying by the fire at Timp Lodge.

T-shirts drying by the fire at Timp Lodge.

We had T-shirts drying all over the place on the Lodge’s railings and many turned out quite well. For the next several days after we returned from Timp Lodge we had quite the tie-dye fashion show as students wore their shirts to school. We’ve had the reputation of being “that hippie school” in the past, so I suppose this helps verify our image.

Follow

Get every new post delivered to your Inbox.