Q1. What are solids?
Ans. SUBSTANCES CAN BE EITHER SOLID, LIQUID OR GAS-THE THREE ‘STATES OF MATTER’.
Substances move from one state to another when they are heated or cooled- boosting or reducing the energy of the particles they are made of. In solids, particles are locked together, so solids have a definite shape and volume. In liquids, particles move around a bit, so liquids can flow into any shape-but stay the volume. In gases, particles zoom about all over the place, so gases spread out to fill containers of any size or shape. When a substance is normally a liquid but turns into a gas, this is called a vapour.