Check out these fun and simple science experiments that your students are sure to love. To see these in action, be sure to check out our Facebook page for updated videos!
Colored Rock Candy
Materials: granulated sugar, small jar, hot water, food coloring, pencil, string, small bead or something to act as a weight
1. Fill the jar with hot water and stir in a spoonful of sugar at a time until the sugar no longer dissolves.
2. Thread the string through the bead and tie a knot at its end. The bead will act as a weight.
3. Wrap the other end of the string around a pencil. Rest the pencil on the mouth of the jar and allow the bead to dangle in the sugar water. The bead should not touch the bottom of the jar.
4. Place the jar in a warm place and let the sugar water stand undisturbed for a week or more. After a few days, you might have to carefully break and remove the crust of sugar crystals at the top so that the water can continue evaporating.
What Happens: Cube-shaped sugar crystals form on the stick, and you’ve made rock candy!
Why this Happens: Water molecules move slowly up into the air as water vapor during the process of evaporation. As more and more water evaporates, sugar atoms draw close together, forming cube-shaped sugar crystals. And that’s just what you’ll see left behind on the string after the water is all gone!
Alka Seltzer Lava Lamp
Materials: vase or water bottle, vegetable oil, water, food coloring, alka seltzer, salt
1. Fill vase or water bottle about 2/3 with oil
2. Add water until the vase has only 1-2 inches of air space left at the top
3. Add 5 drops of food coloring
4. Add Alka Seltzer ¼ tablet at a time. When the bubbles slow down, add another ¼ tablet
5. Experiment with any other additions you want, such as sugar and salt.
What Happens: The Alka Seltzer reacts to make the bubbles, which stirs the oil and colored water together.
Why this Happens: Two of the ingredients in the Alka Seltzer tablet include sodium bicarbonate (aka baking soda) and citric acid. When the tablet is dissolved, the ingredients mix together and carbon dioxide (bubbles) is released. The bubbles mix the oil and colored water, which would otherwise remain separated.