Matter & Energy


Matter is composed of atoms or groups of atoms called molecules. The arrangement of particles in a material depends on the physical state of the substance. In a solid, particles form a compact structure that resists flow. Particles in a liquid have more energy than those in a solid. They can flow past one another, but they remain close. Particles in a gas have the most energy. They move rapidly and are separated from one another by relatively large distances.

Boyle’s Law of Gas

Boyle’s law, developed by English scientist Robert Boyle, states that:

The smaller the volume a given amount of gas is squeezed into, the greater the pressure the gas exerts on the walls of its container. Boyle's law, a mathematical equation that more precisely describes this relationship, states that at constant temperature, the volume of a given quantity of gas varies inversely with the pressure exerted on it. Mathematically, this relationship can be expressed:

V = k (1/P)

where V is volume; k is Boltzmann’s constant (equal to 1.38 × 10-23 and named for the Austrian physicist Ludwig Boltzmann); and P is pressure. If the pressure on a given amount of gas is doubled, for example, its volume will decrease by one-half (as long as the temperature of the gas remains unchanged). Conversely, if the pressure is decreased by one-half, the volume will double.