You probably have seen Lava Lamps in stores. These lamps plug into the wall and can get rather warm. They contain materials that are unsafe to use at home. Here's a simple way to make a lava lamp using materials you can find in your kitchen.
A clear bottle
food coloring (optional)
Fill the water about two-thirds full of water. Add a drop or two of food coloring, if you want. Pour about an inch or two of oil on top of the water and let the oil settle on top of the water. Pour a stream of salt on top of the oil and watch your lamp go! Keep adding salt to keep the lamp moving.
Making Glue from Milk
Most people buy glue at the store to use when they need to stick things together. Store bought glue is convenient, but for fun, you can make your own glue from milk. It’s fun and it’s easy.
Just follow these steps.
Skim milk (do not use whole or 2% milk)
Coffee Filter Paper (cone type works best)
Mix 1 cup of milk and ¼ cup of vinegar. Let the mixture sit for 10-15 minutes. The milk will separate and small pieces of a white solid will form. This white solid is some of the proteins in milk (casein) and will end up becoming the glue.
Place the coffee filter paper over a tall glass. Pour the milk/vinegar mixture into the filter. Pour a little bit at a time so the mixture doesn’t overflow the filter. Make sure the bottom of the filter is above the level of liquid in draining into the glass. Let the filter sit for 10-15 minutes so most of the liquid is removed.
Pour the solids into a clean bowl or plastic container. Add two teaspoons of baking soda to the solids and mix. Listen carefully—you will be able to hear the baking soda react with the extra vinegar and you may even see the some bubbles. Add about one teaspoon of water and mix. You’ve made glue. Now try it out on some paper!
Why does it work?
Milk is a suspension—solids are suspended in the liquid (not dissolved like in salt water). When you add vinegar (an acid), some of these suspended solids (the protein, casein) change their shape and can no longer be suspended. The casein forms the gloppy solid that is filtered from the liquid. Baking soda (a base) is then added to neutralize the acid and change the protein back into a shape that is more fluid. This becomes the glue. Water can be added to give the glue whatever consistency you would like.
Separating Dyes in Water
Sometimes, people want to know what is in a mixture. Scientists use a process called chromatography (kroh-muh-tog-ruh-fee) to separate different parts of a mixture. Dots of the mixtures—different colors of washable markers—are placed on a piece of coffee filter paper. The end of the paper is put into water. As the water moves up the filter paper, it carries the dye from the marker. Different dyes move up the paper at different rates and become separated. While this may sound very complicated, it’s actually an easy process to do at home.
Coffee Filters (cone type)
Water-soluble markers (marked washable)
1. Put a small amount of water in the bottom of a paper cup. The water should come up about one quarter inch from the bottom of the cup.
2. Cut the coffee filter paper into rectangles approximately one half inch wide by four inches long.
3. Place a small spot of marker approximately one half inch from the bottom of the paper. The spot should be above the level of the water in the cup.
4. Use a binder clip to attach the filter paper to a pencil, so that the top of the paper is attached to pencil and the bottom hangs free.
5. Place the pencil across the top of the glass so the bottom of the paper is immersed in the water. Be sure that the spot of marker is above the level of the water and that the paper doesn’t touch the sides of the cup.
6. Watch as the water moves up the paper. The spot of color will start to move up the paper as well. If the marker is a mixture of dyes, the different colors will start to separate.
Things to think about
Did the colors separate the way you expected?
Which colors separated the most? The least?If you have several different sets of markers, try different shades of one color (greens and purples work well). Do the shades separate with the same pattern?