What is the process in which an unstable atomic nucleus emits charged particles or energy or both?
a. radioactivity
b. oxidation
c. decomposition
d. none of the above

Option (A)

Explanation:

Radioactivity is defined as a process in which an unstable atomic nucleus decays continuously and after a specific period of time changes into a much more stable element. During this time of decay, the nucleus emits charged particles (energy) which are known as the α, β and γ particles. These are often emitted in the form of electromagnetic energy and are very dangerous to health.

The radioactive elements decay at a certain rate which is commonly known as the half-life. Half-life is basically defined as the time required by a radioactive substance to decay half of its initial composition.

Thus, the correct answer is option (A).

relative humidity is a measure of the amount of moisture in the air relative to the total amount of moisture the air can hold.

so d