Newton's Laws(Newton's Third Law of Motion)

What is there for every action?

An equal and opposite reaction

In other words, when an object exerts a force on another object:

The second object exerts force of the same magnitude but in the opposite direction on the first object

What happens when a gun is fired?

A bullet fires and the gun recoils

What is the recoil the result of?

Action reaction force pairs

What happens as the gases from the gun powder explosion expand?

The gun pushes the bullet forward and the bullet pushes the gun backward

Why does the acceleration of the recoiling gun smaller than the acceleration of the bullet?

Because acceleration is inversely proportional to mass, and the bullet as a rule has a smaller mass than the gun, and is more easily accelerated