Question

Praveen heated a beaker containing water. He took a few coloured paper pieces and added them in the water. He observed that the paper pieces started moving. Then, he heated a piece of iron, but did not observe any movement of iron particles. Why? Explain.​

Answer 1

because the paper is light and can float on water while the iron is heavy and sank into the water
moreover the molecules of paper is less closely packed than that of iron

Answer 2

Answer:

When a liquid, presumably water is heated, the molecular matter of water start moving upward from the bottom of the container.

- This reminds us of the fact that the energy flow in heating is such that the cold matter deposits at the bottom, and as the matter gets heated, if tends to flow upwards.

- And at the boiling point, the water molecules gets vapourised and turn themselves into steam.

- Because of this movement, the bits of paper dipped in the container also show movement, as their mass is too weak when compared to the mass of water moving due to heating.

- On the other hand, the iron particles are much heavier when compared to the mass of water moving due to heat.

- That is why the movement of water due to heat does not have any effect on the iron particles and they do not move

Explanation: