Chapter 2, Problem 2.11QP

Interpretation Introduction

Interpretation:

All atoms of an element has same atomic number, although they may have different mass number need to be explained.

Concept introduction:

The total number of protons in an atom is said to be its atomic number.  By using the total number of protons and neutrons all the atoms can be identified.  Atomic number is denoted by “Z”.

The total number of neutrons and protons of an atom is said to be its mass number.  By using the total number of protons and neutrons all the atoms can be identified.  Mass number is denoted by “A”.

An atom is always said to be neutral.  Therefore for the charge to remain neutral the total number of electrons must be equal to total number of protons and hence, the atomic number does not change for all atoms of an element.  But the total number of neutrons can change, which leads to the atoms having different mass numbers for the atoms present in an element.  The atoms of an element having same atomic number but different mass number are known as isotope.