Floating and Sinking Substances
Floating and Sinking Substances: Overview
This Topic covers sub-topics such as Dead Sea, Floating on Water, Boiling of Water, Sinking in Water, Oil in Water, Sugar in Water, Iron Nail Sink in Water, Objects Immersed in Salt Water, Thickness of Substance and, Aluminum Foil Float in Water
Important Questions on Floating and Sinking Substances
Which factor is responsible for the increase in the density of Dead Sea?

Why can nobody sink in the Dead Sea?

An iron nail floats in water.

Will these objects float or sink. Write their names under the right column.
These will float | These will sink |

Take a bucket filled half with water. Put a ball pen with a cap fitted on it in the water. See whether it floats or sinks? Now remove its cap and put the pen and the cap separately in the water. What happens now? This time remove its refill also and now again put the pen, its cap and its refill separately in water. Now see what things float in water? Put the pen in different positions like straight, inclined, etc in water and observe it.
In which condition, does the empty pen sink? Try to find out why did this happen?

You must have seen oil above the surface of cooked vegetables and pulses. Why does it happen?

Take a small, transparent glass or plastic bottle. Fill it half with water, put drops of oil in it and close it tightly. Now shake it properly. What do you see inside the bottle? Now keep the bottle stable for some time and see what happens?
Where do you see oil in water?

Take a small, transparent glass or plastic bottle. Fill it half with water, put drops of oil in it and close it tightly. Now shake it properly. What do you see inside the bottle? Now keep the bottle stable for some time and see what happens?
Does the oil dissolve in water?

Mark for the things that float. Mark
for those that sink.
Things to be put in water | I guessed before I did it | I saw when I did it |
(a) Empty bowl (Katori) (b) After putting in small pebbles, one-by-one |
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Iron nail or pin | ||
Matchstick | ||
(a) Empty plastic bottle with its lid closed (b) Bottle half-filled with water (c) Bottle full of water |
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Aluminium foil (from medicine packing) (a) open and spread out (b) pressed tightly into a ball (c) in a cup-like shape |
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(a) Soap cake (b) Soap cake on a small plastic plate |
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A piece of ice |

A wooden boat or an iron ship floats on water. But a needle or nail sinks in water. Why does this happen?

Find out why ice floats on water. How icebergs stay afloat.

You have been given some mishri pieces (lumps of sugar). Find some ways to dissolve them quickly.

What are the things that we put in water to make tea? Which of those things dissolve in water?

A lemon is put in water and salt is added one spoon at a time. The lemon slowly floats up. The lemon floated because

You put a steel plate on water? Would it sink or float? What would happen to a steel spoon?

Have you ever seen anything float on water? Was it a paper boat or a piece of wood or anything else?

Have you ever seen anything float on water?

Put some objects in water and observe what happens.
Name of the object | What happened? | Why this happened? |

Put some pebbles in the floating bowl in a bucket. Keep on putting pebbles until it sinks. After putting how many pebbles did the bowl sink.

Complete the below-given table.
Name of things | Put on the water | |
Float on water | Sinks | |
Pencil | ||
Rubber | ||
Marble | ||
Scale | ||
Stone | ||
Wax | ||
Steel bowl | ||
Plastic Mug | ||
Key |
