Answer:
diamond is denser because it is more tightly packed than coal
Atomic mass / mass number / atomic weight
(all of which mean the same thing)
Bohr's atomic model proposed that electrons move in specific orbits around the nucleus of an atom.
Explanation:
atom changes from a ground state to an excited state by taking on energy from its surroundings in a process called absorption. The electron absorbs the energy and jumps to a higher energy level. In the reverse process, emission, the electron returns to the ground state by releasing the extra energy it absorbed
