In this post it is written definition, key word, key points in the short detail of class nine subject science . Matter in our surroundings Matter:- anything which has mass and occupies space is called matter. 1.1 Physical nature of matter 1.1.1 Matter is made up of particles 1.1.2 How small are these particles of matter?? 1.2 characteristics of particles of matter 1.2.1 particles of matter have space between them 1.2.2 particles of matter are continuously moving Diffusion :- The intermixing of particles of two different types of matter on their own is called diffusion. 1.2.3 particles of matter attract each other 1.3 states of matter Matter around us exist in three different states - solid, liquid and gas. The state of matter arise due to the variation in the characteristics of the particles of matter. 1.3.1 The solid state 1.3.2 The liquid state The gases from the atmosphere diffuse and dissolve ...