Suggested Grades
4+
Objective
Students will see the effects of density when a variety of liquids are poured on top of each other and when a variety of objects are dropped into each one.
Materials
- at least 7 small clear plastic cups
- light corn syrup
- lamp oil
- milk
- water
- a piece of cork
- a piece of a candle
- a piece of metal
*Each object should also be the same size as each other.
Method
Do this activity as a demonstration or in class groups.
Part 1
- Pour liquids in each glass in the order shown below. Pour out a glass of each liquid combination, so you will have 3 filled glasses in total.
- 1) corn syrup, milk, oil
- 2) milk, oil, corn syrup
- 3) oil, corn syrup, milk
- What happened? Draw your observations. Why did this happen? Organize the liquids from most to least dense.(You should be able to some layers clearly because each liquid has a different density. If the layers combine then the top layer has the heavier density than the one that it was poured on top of.)
- Try the experiment with other liquids.
Part 2
- Pour out a little of each liquid in separate glasses. Include a glass with a little water in it. So, you will have 4 glasses of liquids in total.
- Try dropping a piece of cork, into the middle of each liquid. In which liquids did it sink? In which liquids did it float? Record.
- Fish out the cork, or use a new piece that is equal in size and weight, and repeat the process with the pieces of candle and metal.
- Which objects floated the most? Which objects sank the most? Organize the objects for most to least dense.
- Try the experiment with other liquids.