Question

we can easily move our hand in air but to do some through a solid block of wood we need a Karate expert

Answer 1

It is because force of attraction between molecules, it is very low in air so we can move freely while it is very high in solids

Answer 2

As the particles of air are freely movable and they have all the characteristics of gases but the same in solid block of wood the particles are closely packed and is not easy to break..
Karate experts could break it as they apply more force on it..
And this is the reqson y we coupd move our hands freely in air and could not do the same in solid..

HOPE IT HELPS FRND...