You don’t need a lab to do chemistry. Here are a few simple chemistry experiments designed for curious five to eight year olds.
#1) Pepper Popping
- bowl with water
- dish soap
- tooth pick
Sprinkle the pepper on the water. Dip a tooth pick into dish soap and place the tooth pick with soap in the water. Watch the pepper run away.
Discussion Topic: Surface tension of water
Two sentence explanation: Water molecules like to stick together and will form a thin skin on top of the water (like a filled balloon). Dish soap pops water’s surface tension, sending a ripple effect through the water and pushing back the pepper. (Note: This is NOT a reaction between the pepper and the dish soap.)
Follow up questions: What else could you balance on top of water? Could you “pop” anything else with dish soap?
#2) Growing Balloons
- An 8 inch balloon filled with water (not filled to busting)
- A clothe measuring tape (or a string that won’t stretch)
- A permanent marker
- A freezer
Using the permanent marker, draw a line around the middle of the balloon (This is to make sure you measure in the same place before and after). Measure around this line, and record the length. Place the balloon in the freezer overnight. Measure around the balloon again and record the difference.
Discussion Topic: Water’s molecular structure
Two sentence explanation: Water molecules fit together more tightly in liquid form than they do as a solid. When you freeze the balloon, water expands inside the balloon and the balloon grows.
Follow up questions: What would happen if you filled a glass jar completely full of water and froze it? Do you think water takes up more or less space as a a vapor (steam)? Why or why not?
#3) Rip Van Winkle Pennies
- Five shiny pennies
- a glass jar
- 1/4 cup white vinegar
- 2 Tbl hydrogen peroxide (found in the first aid section of grocery stores)
Combine the vinegar and hydrogen peroxide in the glass jar. Place the pennies in the vinegar solution, and let them “rest” for 2 hours. (Note: The jar should be placed well out of a child’s reach! The liquid should NOT be swallowed.) The pennies will age 100 years in less than one day.
Discussion Topic: Oxidation
Two sentence explanation: Oxygen likes to steal electrons from other elements, and the process of oxygen stealing electrons makes metals rust, turn black, or otherwise wear out. The combination of vinegar and hydrogen peroxide makes it easier for oxygen to steal the copper penny’s electrons (so it happens faster).
Follow up questions: Can you oxidize anything besides a penny in this solution? What would happen if you added baking powder to the solution?
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