Chapter 2.3, Problem 1RC

a)

Interpretation Introduction

Interpretation:

The atomic number of an element if one of its isotopes has neutrons of $117$ and mass number of $195$ has to be identified.

Concept Introduction:

Mass number (A): Mass number of an element is sum of protons and neutrons of the atom.

$\text{A= Number of protons}\left(\text{P}\right)\text{ + Number of neutrons}\left(\text{n}\right)$

Consider an element X with atomic number and mass number,

${}_Z^A\text{X}$

Where,

A is mass number (sum of protons and neutrons) and Z is atomic number (number of proton or electron)

b)

Interpretation Introduction

Interpretation:

Out of given two isotopes the one that provides more information has to be interpreted.

Concept Introduction:

Mass number (A): Mass number of an element is sum of protons and neutrons of the atom.

$\text{A= Number of protons}\left(\text{P}\right)\text{ + Number of neutrons}\left(\text{n}\right)$

Consider an element X with atomic number and mass number,

${}_Z^A\text{X}$

Where,

A is mass number (sum of protons and neutrons) and Z is atomic number (number of proton or electron)