Which law states that for every action there is an equal and opposite reaction?

• A. Newton's Third Law
• B. Newton's First Law
• C. Law of Conservation of Mass
• D. Archimedes' Principle

Answer: (A)

Action and reaction forces come in equal and opposite pairs. When one object pushes on another, the second pushes back with the same magnitude in the opposite direction. This is Newton's Third Law. It explains everyday things like how you push off the ground to jump, why a gun recoils when fired, or how a rocket moves by throwing exhaust backward. The other options describe different ideas—inertia from the First Law, mass conservation in reactions, and buoyancy from Archimedes' principle—so they don’t capture the paired force idea that this law expresses.