Sound is a kind of energy created when something vibrates. When this vibration reaches an ear, it is translated into what we recognize as a sound. Sound vibration must travel through matter. Therefore, it can travel through air and water but not through vacuum.

Lord Kelvin, working in Scotland, developed the Kelvin scale in 1848. His scale uses molecular energy to define the extremes of hot and cold. Absolute zero, or 0 K, corresponds to the point at which molecular energy is at a minimum. The Kelvin scale is preferred in scientific work, although the Celsius scale is also commonly used. Temperatures measured on the Kelvin scale are reported simply as K, not °K.

T (in °C) + 273.15 = T (in K)

T (in K) − 273.15 = T (in °C)

Argon gas is used in fluorescent and incandescent light bulbs to stop the oxygen in the light bulbs from corroding the hot tungsten filament.

The use of argon in light bulbs prevents the evaporation of the tungsten filaments, which results in increased light bulb life.

Argon is also used to create an inert atmosphere for growing semiconductor crystals, arc welding and for processes that need protection from other kinds of atmospheric gases.