Mass and energy are equivalent. I'm doing the same test right now.
Answer:
Protons and Neutrons are found in the nucleus D would be your answer
Explanation:

why momentum is a property of moving objects, but not of stationary objects?
Answer:
Hi, There!-
Momentum is a property of a moving object because velocity is needed to get the momentum. Only a moving object has velocity.
Hope this Helps!

Answer: Hello! An objects speed is constant and has the units meters per second (m/s); thus, it does not change overtime. Acceleration is a rate of change where the speed does either increase or decrease overtime from its inital value; its units are meters per second second (m/s/s). I hope that helps!