Chapter 30, Problem 10Q

To determine

Number of neutrons emitted when a Uranium nucleus decays via alpha decay

Answer to Problem 10Q

Solution:

WhenUranium nucleus decays via alpha decay, number of neutrons will be 144

Explanation of Solution

The ${}_{92}{}^{238}U$ nucleus decays via a alpha decay in to ${}_{90}{}^{234}Th$.This is in the formof ${}_Z{}^{A}X$ this form. We have to determine the number neutrons.

Where Z is the number of protons in the element which is 90

A is the mass number, which is the number of protons plus the number of neutrons which is 234

X is the chemical symbol of the element, and it must correspond to the atomic number which is Thorium here.

$\text{Neutrons}=A-Z$

The number neutrons form above relation is

$\begin{array}{l}\text{Neutrons}=\text{ 234}-90\\ \text{Neutrons}=144\end{array}$