Changes of States of Matter

All matterScience meaning: Matter is any substance (often a particle) that has mass, and also volume (occupies space). Matter exists in three states, solid, liquid and gas and is made up of small particles, which may be molecules, atoms or ions. English meaning: A situation or subject that is being dealt with or considered. e.g His departure complicates matters even further. is interchangeable, that is it can change from one state to the other, as a result of a change in temperature.

• Melting: When a solid changes into a liquid, it is called melting, for example, ice block to water. The temperature at which solid changes into a liquid is called “melting point”. Solid particles gain enough energyEnergy is the ability to do work. Energy exists in several forms such as heat, kinetic or mechanical energy, light, potential energy, and electrical energy. Units of Energy: The SI unit of energy is the joule (J) or newton-meter (N * m). The joule is also the SI unit of work. to overcome the attractive forces of the surrounding particles.

• Condensation: This is when gas changes into a liquid, for example, steam to water.

• Boiling/Evaporation: When a liquid changes into a gas, evaporation takes place, for example, water into steam. The temperature at which liquid changes freely into its vapour is called its “boiling point”. For the case of silver, it is 2162°C, while in the case of water it is only 100°C. Boiling arises as a result of the liquid particles, gaining enough kinetic energy to overcome the attractive forces of the surrounding particles.

• Sublimation: This is when solid changes directly into a gas, for example, iodine crystals to iodine vapour.