Question

All matters in the universe exist in three states namely solid, liquid and gas.
(a) Why do solid substances have definite shape?
(b) Write any two properties of a solid substance.
(c) Will the solid substance expand on heating? Why?

Answer 1

Solid have a correct shape because its particles are held tightly at a certain position by the attractive forces.

1. it has its own particular mass, 2. Its volum is fixed and does not change.

Yes, because the hotter a substance more its atoms move voilenty, so it takes more space than it needed previously. So the substance expand.

Answer 2

atoms in a solid substance are closly packed