Give reasons
(a) An gas fills completely the vessel in which it is kept.
(b) An gas exerts pressure on the walls of the container.
(c) An wooden table should be called a solid.
(d) We can easily move our hand in air but to do the same through a solid block of wood we need a karate expert.
Answers
a). As we know that atoms or particles of gases are constantly moving and loosely packed so when gas is filled into the vessel its particles covers the vacant area and thus, fill the vessel completely.
b). Gases exerts pressure on the walls of container. This is because the particles or atoms of the gases moves constantly and collide with the walls of container. Due to the collision it creates some force and hence it puts pressure on the walls of the container.
c). An wooden table should be called as solid only if it satisfy the property of Solid. If it is solid then it must have fixed shape and volume. Wooden table should not be compressed. It must be heavy because solids have high density. It doesn't fill the container completely in which it is kept. Solids do not flow they are rigid. However the conclusion is that, that Wooden table satisfy all the property of Solids so it can be called as Solid.
d). We cannot move our hand through a solid plank of wood but we can move our hand through air easily. This is because the cohesive force of air is negligible but the cohesive force of solids are very high. So that we need an karate expert to move his hand through plank of wood.
A- due to less intermolecular force of attraction and high kinetic energy
C- Because it doesn't flow and particles r tightly packed
B- Due to high kinetic energy
D- Due to high intermolecular force of attraction