Chapter 20, Problem 74RQ

Interpretation Introduction

Interpretation:

The amount of technetium $-99$ left after four half-life periods from a sample of technetium $\text{-99}$ with a mass of $\text{9}\text{.00 mg}$, is to be determined.

Concept Introduction:

The process in which a subatomic particle and a nucleus of an atom collide with each other in order to form one or more nuclides is known as a nuclear reaction.

These nuclides are different from the nuclides which are present initially.

A radioactive substance is a type of substance which gives electromagnetic radiations or particles from an unstable nucleus.

The radioactive decay is used to represent the phenomenon as the rate at which the radiations emitted is based on the concentration of radionuclides. In radioactive substance decay, the number of radionuclides that is left, it decreases and the intensity of the radiations also decay or decreases.

Amount of the original isotope remains after a certain interval of time is given as:

$\text{mass remains = }\left({\text{1/2}}^{\text{n}}\right)\text{ \&*\#x00A0;}\left(\text{original mass}\right)$, where n is the number of half-lives