things fall towards the center of the earth
The opposite reaction pair to gravity is the normal force.
friction is a reaction beetween matter and gravity
The reaction force in this scenario is the Earth's gravity pulling on the Sun. According to Newton's third law of motion, for every action force, there is an equal and opposite reaction force.
No. Gravity is one of the four fundamental forces, and has nothing to do with chemistry.
While he's in the air, the reaction force is air resistance and when he's in the water the reaction force is upthrust. Hope this helps.
The normal reaction to gravity is attraction. Gravity tries to pull the two objects closer together. A negative reaction would be that the two objects try to push apart. Sounds like science fiction.
While he's in the air, the reaction force is air resistance and when he's in the water the reaction force is upthrust. Hope this helps.
The Earth pulls down on you, but you pull up on the Earth!
Continental drift or gravity pulling
The reaction force to gravity is the ground pushing back up against you with an equal force to support your weight. This is known as the normal force.
The action is the Earth's gravity pulling down on the book. The reaction is the book exerting an equal and opposite force upwards on the Earth, though it is so small that it is essentially negligible.
No, it's a force. Gravity just keeps you from floating around. For a reaction there is always an equal and opposite reaction. Newton said that. Look up Newton's Laws of Physics (or motion).