Question

1. Give reasons:
a) A sponge can be pressed easily; still it is called a solid.
b) Water vapour have more energy than water at same temperature.
c) A balloon kept in sun burst after sometime.

Answer 1

1.
A sponge has minute holes,in which
air is trapped, when we press it,the air is expelled out and we are able to compress it.sponge is a porous solid.

2.
It is because water vapour being a gas exerts much more pressure than waterwhich is a liquid at the same temperature. water is heated it turns to gaseous vapour and the steam gives of a hot heat gas , when we put at high pressure it gives more energy.

3.
A balloon when kept in sun brusts after some time because outside the temperature is high and due to that the kinetic energy increases and the molecules of gas particles inside exerts a pressure on the walls of the balloon so it will continue to expand and there a stage will come that the balloon will brust.

Answer 2

Answer:

1. a sponge has minute holes in which air is is trapped when we press it the air expelled out and we are able to compress it.

2. it is because water vapour is being a gas exerts much more pressure that water which is a liquid at the same temperature. water is heated it turns to gaseous vapour and steam gives of a hot has when we put it at the higher pressure it gives more energy.....

Hope this may help you