Question

1. which is not an assumption about particles in a gas according to the kinetic theory?

under ordinary conditions, forces of attraction between particles can be ignored.
the motion of one particle is unaffected by other particles unless the particles collide.
the forces of attraction among particles keep the particles close together.

Explanation:

According to the kinetic theory of gases, gas particles are in constant random motion and the forces of attraction between them are negligible under ordinary conditions. Gas particles move freely and are not kept close together by attractive forces (unlike in solids or liquids). Also, the motion of one particle is unaffected by other particles unless they collide.

Answer:

The forces of attraction among particles keep the particles close together.