Liquid Layers

Do oil and water mix?

Oil and water have different densities. Oil floats on water because it is less dense than water. A liquid that floats is lighter or less dense than a heavier or more dense liquid that sinks.

Try the experiment below and explore different densities.

Collect these materials:

Plastic cups (4)
Clear straw
Plasticine clay
Eye dropper
Rubbing Alcohol
Salt
Glycerin
Water
Food Coloring (4 colors)
Measuring cup
Tablespoon

1. Put in cups:

• 59 mL (1/4 cup) water
• 59 mL (1/4 cup) alcohol
• 59 mL (1/4 cup) glycerin
• 59 mL (1/4 cup) water and 30 mL (2 tbsp) salt

2. Make each cup a different color.

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3. Push straw into clay.

Experiment: Can you get the liquids to float on top of each other so that you see four different colors?

Hint: Each liquid has a different density.

Why do you have to shake salad dressing? How can you make an ice cube sink? How does temperature affect a liquid's density?

Density dessert

Demonstrating density

Sinkers and Floaters

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