What happens to the average kinetic energy at a constant temperature? * 1.it increases
2.it decreases
3.it stays the same
4.it disappears

The answer is A, it increases.

As the temperature increases, the average kinetic energy increases as does the velocity of the gas particles hitting the walls of the container. The force exerted by the particles per unit of area on the container is the pressure, so as the temperature increases the pressure must also increase.