The given blanks can be filled with attraction and repulsion.
Gases comprise tiny particles of matter, which are in spontaneous motion. The particles of a gas are colliding continuously with each other and with the container walls. These collisions are considered elastic, that is, no net loss of energy takes place due to collisions. The particles of gases are distinct away from each other by large distances.
There are no interactive forces, that is, repulsion or attraction among the gas particles. The average kinetic energy of gas particles depends upon the temperature of the gas.
