9 Exciting Science Demos and Experiments (Grade 7- Chemistry)

I love seeing the wonder in students' eyes as they witness an extraordinary phenomenon. These demos and experiments will hopefully inspire their curiosity and prompt questions of inquiry about the intricate world around us. Experiments are grouped by topic.

Density

1. Amazing 9 Layer density tower

• http://www.youtube.com/watch?v=-CDkJuo_LYs
• Demonstrates density of both liquids and solids!

2. Dyed ice cube melting in cooking oil

• https://www.youtube.com/watch?v=5XKG2OXeZQw
• Compares density of oil, ice, and water

3. Coke Vs. Diet Coke Experiment

• https://www.youtube.com/watch?v=4wyPPljNdK8
• Demonstrates how amount of sugar in soda can change its density

Freezing point/ Melting point

4.  “Ice fishing” (Fishing an Ice Cube)

• https://sites.google.com/site/chemistrydemos/more-demos-29-32
• Demonstrates how salt affects the freezing point of water

5. Instant Freeze- Soda Ice

• http://www.stevespanglerscience.com/experiment/instant-freeze-soda-ice
• Demonstrates how carbon dioxide concentration can affect freezing point of soda (explanation #1)

6. Homemade ice cream

• http://www.stevespanglerscience.com/experiment/homemade-ice-cream-sick-science
• Demonstrates how salt lowers the freezing point of water

Chemical vs. physical changes

7. Ivory Soap Souffle- microwave trick

• http://www.stevespanglerscience.com/experiment/soap-souffle
• Chemical change or physical change? Why? Can be used as a conversation starter to discussing chemical and physical changes

Solubility & Rate at which Substances Dissolve

8. Rock candy

• https://www.youtube.com/watch?v=4uXQ2Uoaa_M
• http://www.gluesticksblog.com/2011/09/homemade-rock-candy.html
• The process of making rock candy can be used to discuss how temperature affect solubility and how heating, stirring, and surface area (granular sugar vs. sugar cubes) affects the rate at which substances dissolve

pH- acidic and basic characteristics

9. Red cabbage indicator

• http://www.stevespanglerscience.com/experiment/red-cabbage-chemistry
• Demonstrates acidic or basic properties of various substances

Please leave a comment if you have any additional ideas or exciting demos for teaching chemistry!