To know if a matter is solid, you can observe through its physical characteristics.1. Definite Shape and Volume- A solid has a fixed shape and does not conform to the shape of its container. It also has a constant volume that does not change easily.2. Rigid Structure- The particles in a solid are closely packed together in a fixed, orderly arrangement. This gives solids their rigidity and resistance to changes in shape. In simple terms, they keep their shape. That’s why solids don’t change shape unless they are cut or break. 3. Incompressibility- Solids cannot be compressed easily because their particles are already tightly packed.4. Limited Particle Movement- The particles in a solid vibrate in place but do not move freely, unlike in liquids or gases. Example of solids include metal, wood, glass, plastic, etc.