What are the characteristics of the particles of matter?

The mass per unit volume of a substance is called density. (Density = Mass/Volume ). Arrange the following in order of increasing density – air, exhaust from the chimneys, honey, water, chalk, cotton and iron.

Give reasons

(a) A gas fills completely the vessel in which it is kept.

(b) A gas exerts pressure on the walls of the container.

(c) A wooden table should be called a solid.

(d) 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.

Liquids generally have a lower density than solids. But you must have observed that ice floats on water. Find out why.