Chapter U1.14, Problem 9E

Interpretation Introduction

Interpretation:

Five elements that have radioactive isotopes on the periodic table must be given. The neutron to proton ratio must be calculated for all those in decimal form.

Concept introduction:

Radioactive elements are those which have very high (greater than 1.54) neutron to proton (n/p) ratio.

Explanation of Solution

The name of five elements having radioactive isotopes are Uranium, Neptunium, Plutonium, Americium and Thorium.

$\text{U}$ and $\text{U}$ both have 92 protons and 146 and 143 neutrons respectively. Thus, n/p ratio is $\frac{146}{92}=1.587$ and $\frac{143}{92}=1.554$ respectively.

In this way, all the n/p ratios are calculated for the listed isotopes.

The neutron to proton ratio of $\text{U}$ and $\text{U}$ is 1.587 and 1.554 respectively.

The neutron to proton ratio of $\mathrm{N}p$ and $\mathrm{N}p$ is 1.527 and 1.538 respectively.

The neutron to proton ratio of $\text{P}\text{u}$ and $\text{P}\text{u}$ is 1.574 and 1.564 respectively.

The neutron to proton ratio of $\text{A}\text{m}$, $\text{A}\text{m}$ and $\text{A}\text{m}$ is 1.537, 1.547 and 1.558 respectively.

The neutron to proton ratio of $\text{T}\text{h}$ is 1.578.