Create zombie raisins with household items or a bottle of soda within minutes. Below you’ll find a quick, science experiment that will teach preschool and elementary school kids a little about buoyancy. This is great at Halloween, or anytime for your zombie-obsessed child!
- 6-8 “Zombies” aka fresh raisins
- A can or bottle of clear pop/soda like club soda, Sprite or 7-Up.
- Alternatively, use baking soda and vinegar instead of a bottle of soda.
- A tall glass or clear plastic cup
What Mystery Are We Solving?
The raisins that are heavier than the fluid, sinks to the bottom of the glass, but they don’t stay there. What makes the zombie raisins move after lying “dead” on the bottom?
There is nothing particularly dangerous about this experiment. Have an adult present to help and use common sense.
To prevent clogging the drain, remove the raisins from the glass before pouring the mixture down the drain.
How To Make Dancing Raisins
- Open the bottle of clear soda and pour some into a glass.
- Separate the raisins
- Add the raisins one-by-one to the glass and see what happens.
- The raisins sink to the bottom as if “dead.”
- Wait a few minutes and watch how the zombie raisins start moving again.
If you don’t have a see-through bottle of soda, then
- Fill the glass halfway with water.
- Add 1 teaspoon baking soda.
- Drop the raisins one-by-one in the glass of baking soda water.
- Add vinegar until the glass is ¾ full.
- Watch how the sunken raisins starts moving.
What Just Happened Here?
Raisins are denser than the soda solution or the baking soda dissolved in water. Therefore, the raisins sink to the bottom of the glass.
Baking soda and vinegar create carbon dioxide gas like the carbon dioxide gas seen as bubbles in a soda can. The bubbles attach to the uneven surface of the raisins making the zombie raisins less dense. Buoyancy measures the degree that an object sinks or float according to its density. If the object is denser than the fluid, it sinks. When it becomes lighter it will float.
The zombie raisins dance-float to the top where the bubbles are released. The raisins become heavy again and drop back to the bottom of the glass until CO2 bubbles attach to it again. The cycle continues until all the CO2 has escapes to the surface and the soda drink becomes flat.
The chemistry formula is HC2H3O3 (acetic acid in vinegar) +NaHCO3 (bicarbonate soda in baking soda) — > CO2 gas (carbon dioxide gas bubbles) + H2O +NaC2H3O2 (sodium acetate)