The directions told us to choose something fun--a theme we would enjoy. I asked Lewie one Saturday afternoon, and he replied, "Minecraft Potions." Hmmmm. I immediately googled Minecraft Potions, which didn't turn up good results. However, when I googled science fair potions, we were in luck!
Lewie had to use the scientific method. He had to ask a question, follow it up with a hypothesis, explain the experiment (materials, procedure, and observation), and then write his conclusion. Thanks to some wonderful ideas of other "science fair moms" before me, we decided to make two "potions."
His first potion mixed vinegar with baking soda. (He guessed it would turn brown and smell bad.) In reality, when the two ingredients were mixed together, bubbles came to the surface and made a hissing sound. (We later learned that the reaction occurred because both ingredients create the gas carbon dioxide. These were the bubbles wanting to escape the surface.) It didn't turn brown, but it did smell bad--like vinegar.
The next potion used water, vegetable oil, food coloring, and Alka-Seltzer tablets. Lewie predicted the potion would explode. (It probably would have if we used more than the recommended amount of Alka-Seltzer.) We took a one liter bottle and filled it with a cup of water. The rest of the bottle was filled with vegetable oil. Then we placed ten drops of orange food coloring. The water and the food coloring sunk to the bottom while the oil rested on top. (Turns out--water is denser than oil.) When we put 1/2 an Alka-Seltzer tablet in the bottle, water bubbles with the orange food coloring rose to the surface of the oil creating a "lava lamp" effect. Lewie and I both loved the result. In fact, Lewie was so proud of his creation, he thought we could become rich by making more of them and selling them on Amazon!
At the end of the fair, he was called up to the stage to receive his participation medal and certificate. He was only one of six second-graders that participated in the science fair. (There's about 60 students in Lewie's second-grade class.) My darling walked up the stairs, waved to the audience, received his award, and then smiled and waved at us. It was one of those proud moments I'll keep sealed forever in my heart.