SSC MTS EXAM

Detailed explanation-1: -Changing states of matter occur when matter loses or absorbs energy. When a substance absorbs energy; the atoms and molecules move more rapidly and this increased kinetic energy pushes particles far enough that they change form. This energy is usually heat or thermal energy.

Detailed explanation-2: -Energy is consumed to change a substance from solid to liquid to gas. Energy is released to change a substance from gas to liquid to solid.

Detailed explanation-3: -Thus any transition from a more ordered to a less ordered state (solid to liquid, liquid to gas, or solid to gas) requires an input of energy; it is endothermic. Conversely, any transition from a less ordered to a more ordered state (liquid to solid, gas to liquid, or gas to solid) releases energy; it is exothermic.