Question

We can easily move our hand in air but to do the same through a solid block we need a kararte expert

Answer 1

This is because there are negligible intermolecular forces in air, so our hand can easily pass through it.
whereas a solid block has a high amount of intermolecular forces, so it is very difficult for us unless we are a karate expert to mover our hand through it

Answer 2

Air is a gas, it has more space in between particles. But solid block of wood is rigid, hence it is difficult to move our hands through it.