or radioactive substance have a half life.

A radioactive element or radioactive substance have a half life

Explanation:

The half life of a radioactive element is defined as the time taken for the atoms of the radioactive elements to decay to half the original number

Radioactive decay

Radioactive decay simply the process by which the nucleus of a heavy radioactive element disintegrates and emits alpha or beta particles along with Gama rays

Law of radioactivity

The law states that when a radio active element decays or disintegrates it forms a new element two places below in the periodic table with emission of alpha particles or two places above the element in the periodic table with emission of beta particle.

step-by-step explanation:

we are given

we have to simplify it

firstly, we will factor it

now, we can cancel like terms

now, we can combine it

so, we get