You put a steel plate on water. Would it sink or float? What would happen to a spoon?
Ans. If I put the steel plate carefully on water, it would float. The spoon would sink.
.Would the cap of a plastic bottle sink or float on water?
Ans. The cap of the plastic bottles would float on water.
Have you seen that some things float on water while others sink? Think how this happens?
Ans. Yes, I have observed that certain things float on water while others sink. Everything displaces water equal to its volume. If the displaced water is more than the weight of a thing, then the thing floats, otherwise it sinks in water.
Do This and Find Out
Do this experiment in groups of four friends. Each group will need a big pot filled with water and the things listed in the table. Put each thing one-by-one in water and observe.
1.Mark (✓) for the things that float. Mark (X) for those that sink.
Take some water in a glass. Put a lemon in it. Now keep putting salt in the water, half-a-spoon at a time. Were you able to float your lemon in water?
Ans.Yes, the lemon started to float on water.
What do you think, the lemon floated in salty water because…….
Ans.After adding salt, the water became thicker and thus the lemon started floating.
Make groups of four friends. For the experiment you will need 4-5 glasses orbowls, spoons, water, and the things listed in the table. Take some water ineach glass. Now try to dissolve one thing in one glass. Observe what happensand note in the table.