Ideal Gas

A theoretical material used in physics and chemistry to describe the behaviors of gases under different conditions. In an ideal gas:

• All collisions between molecules are perfectly elastic (i.e. no energy is lost when individual molecules collide).
• Molecules remain in the gas phase all the way down to absolute zero.
• The molecules themselves have no mass or volume.

Ideal gases don’t exist, but describing ideal gases is useful because the behavior of real gases are similar to ideal gases in many real world situations.