I believe the answer is "When a neutral atom looses an electron to another neutral atom, two charged atoms are created."
Explanation:
Given that,
The mass of rock, m = 2.35-kg
It was released from rest at a height of 21.4 m.
(a) The kinetic energy is given by : 
As the rock was at rest initially, it means, its kinetic energy is equal to 0.
(b) The gravitational potential energy is given by : 
It can be calculated as :

(c) The mechanical energy is equal to the sum of kinetic and potential energy such that,
M = 0 J + 492.84 J
M = 492.84 J
Hence, this is the required solution.
The number of protons determines the element. Many elements also have many isotopes. Such as carbon-14 Carbon-12 and carbon-10.
Both the birth and death rate are expressed per 1000 of the population.