Products must equal which in a chemical reaction?

reactants
atoms
elements
molecules

relationships are meaning less your heart will get broken.: (

Gravity, from the center of mass of the box, extending downward normal force, from the floor under the box, extending upward, equal to gravity push force, acting at a point on the box, extending in the direction of motion friction, acting at any point on the box directly opposite the push, extending directly opposite to the motion