Give reason :- We can easily move our hand in the air but to do the same through a solid block of wood we need a karate expert.
Since air is a gas and the forces of attraction between the particles of gas are very less which makes it easy to separate the particles with the help of an external force and hence we can easily move our hand in air. Whereas in case of solids the forces of attraction are very strong and we need very high force to separate the particles of a solid and hence we need a karate expert for it.
