a is the answer hope this helps
Answer:
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).
The answer to this is option B, all the gas particles have the same velocity
