Chapter 2.1, Problem 2A

Summary Introduction

Introduction:

An isotope is defined as an element having the same atomic number but a different mass number. In the modern periodic table, elements are arranged according to their increasing atomic number. The symbol is derived as,${}_Z{}^{A}X$, where X represents the chemical formula of the element present in the periodic table.

A is the atomic mass which is equal to the sum of the number of protons and the number of neutrons.

Z is the atomic number which is equal to the number of protons.

The nucleus is defined as the sum of the number of neutrons and protons.

$\begin{array}{l}{p}^{+}\to proton \\ n^0\to neutron\\ e^{-}\to electron\end{array}$

Isotopes are defined only in the modern periodic table.