Review of Colors and Chromatography

We had one guest join us for Colors and Chromatography. Here were the activities we accomplished:

• Light Mixing: Into a dark room armed with 3 flashlights and 4 color gels went the kids to explore light mixing. They created cyan, magenta, and yellow. What did they start with you ask? The primary colors of light: red, green, and blue. They had a yellow gel also, but it surprised them by not mixing to make new colors the way they are used to from painting. That's because light mixes additively.



• Marker Mixing: Using regular washable markers and recycled white paper, we mixed and played with red, yellow, and blue to create other colors. Using a standard "kid marker" set, it is pretty hard to get colors which are pure enough to mix well but we did it.



• Colored Pencil Mixing: Do colored pencils work just as well as markers for color mixing? Not unless you press really hard and get solid color over the area. If you color as I normally do with colored pencils, there are still white spots within the colored area which prevent your eyes from accomplishing the trick of mixing the colors.



• Light Separation: Using a prism, we split light into its various colors, looked at the colors from various objects, and examined various light sources. Kids drew what they saw while using the prism (the bending or refraction of light created by the glass material of the prism)



• Marker Separation: We drew pretty pictures on coffee filters with lots of colors and then separated them back out. How you ask? Dip the bottom end of the coffee filter in water and let the water wick up through the artwork. The water will carry the colors along with it. However, each color goes at a different speed. So the colors which make up each marker line are separated out into the primary color components. Try it and you will see and understand better :-)

Review of Small Numbers

We had a great group for learning about Small Numbers before Thanksgiving. We started off outside on chalk drawn number lines. We played with positive and negative numbers with our feet on the number line. We stretched and hopped our way to number combinations in a twister sort of fashion. Put your left foot on -4, put your right foot on 0, now in one big hop put your left foot on -1 and your right foot on +3. You get the idea.

Then we talked about ways to write numbers. I wrote a collection of numbers on the driveway and the kids told me when I was writing "new" numbers. They caught me at 10². Yep I wrote the number 100 in a silly way they told me once I explained the number. We kept going and we discussed 3x10⁴ and they began to see the simplicity of exponential notation.

With those two concepts, we can proceed to Small Numbers. We broke the driveway into sections 10 meters long. Each child or team then divided their section up 10 pieces. I had a little worksheet to go along with this activity where they wrote down how many deci-driveways they made (10¹) and how much of their total driveway section was in each deci-driveway (10^-1). Then we took one deci-driveway and broke it onto 10 pieces - centi-driveways. Do you see how I introduced measurement, ratios, and SI unit prefixes? We went one step further to milli-driveways and that was hard enough to mark in thick sidewalk chalk.



At this point we stepped inside to the microscope, Powers of Ten movie clip, and a number ordering activity. We have a microscope with a magnification of up to 400x and lots of prepared slides. I also made available a scale bar (aka clear ruler with mm markings) so they could really see how big the microscope made things look. Those mm markings are huge through the objective lense! Powers of Ten is a famous (in physics circles) film which takes a couple picnicking by the lake in Chicago and changes the field of view by a power of ten every 4 seconds or so. The distance covered go larger than galaxies and smaller than the nucleus of an atom. This film showed the kids things they can't see in everyday normal life. The last activity was to arrange a set of cards with the numbers in order. There were 5 sets and the numbers got progressively more challenging to order because they got smaller and were written in exponential notation (which is larger 3x10^-2 or 3x10^-3?).