Chapter 2, Problem 2.77SP

(a)

Interpretation Introduction

Interpretation:

Rutherford’s experiment has to be described and how it led to the structure of the atom should be explained.  Also, how was he able to estimate the number of protons in a nucleus from the scattering of alpha particles should be explained.

Concept Introduction:

Atoms: Atoms consist of tiny particles called protons, neutrons and electrons.  Proton and neutrons are present in the nucleus and the electron resides around the nucleus.  The protons number will be same as the electrons count in the atom.

The symbol of an element is ${}_{\text{Z}}^{\text{A}}\text{X}$.

Where,

$\begin{array}{l}\text{A (mass number) = no}\text{.of protons + no}\text{.of neutrons}\text{.}\\ \text{Z (atomic number) = no}\text{. of protons}\text{. (electrons = protons)}\text{.}\end{array}$

(b)

Interpretation Introduction

Interpretation:

The density of the nucleus $\left({\text{g/cm}}^{\text{3}}\right)$ and density of the space occupied by the electrons in $\text{Na}$ atom has to be calculated.  Also whether the results support Rutherford’s model of an atom or not should be explained.

Concept Introduction:

Atoms: Atoms consist of tiny particles called protons, neutrons and electrons.  Proton and neutrons are present in the nucleus and the electron resides around the nucleus.  The protons number will be same as the electrons count in the atom.

The symbol of an element is ${}_{\text{Z}}^{\text{A}}\text{X}$.

Where,

$\begin{array}{l}\text{A (mass number) = no}\text{.of protons + no}\text{.of neutrons}\text{.}\\ \text{Z (atomic number) = no}\text{. of protons}\text{. (electrons = protons)}\text{.}\end{array}$