The first is that the object moves. The second is that a force must act on the object in the direction the object moves.
Answer:
Question 1: protons and electrons
Question 2: atomic number
Explanation: trust me
When light rays<span> enter a </span>new medium<span> at an angle, the change in speed </span>causes<span> them to </span>bend<span> and change direction. ... They change the speed </span>causes<span> the </span>ray to bend<span> or change direction. When </span>light<span> slows down even more when it passes from water into glass.</span>
