Q. 5.60 - An Introduction to General, Organic, and Biological Chemistry

Question

Identify each of the following as alpha decay, beta decay, positron emission, or gamma emission: $(5.1,5.2)$

a. ${}_{55}{}^{127}\mathrm{Cs}⟶{}_{54}{}^{127}\mathrm{Xe}+{}_{+1}{}^{0}e$

b. ${}_{38}{}^{90}\mathrm{Sr}⟶{}_{39}{}^{90}\mathrm{Y}+{}_{-1}{}^{0}e$

c. ${}_{85}{}^{218}\mathrm{At}⟶{}_{83}{}^{214}\mathrm{Bi}+{}_2{}^4\mathrm{He}$

Step-by-Step Solution

Answer

Below, alpha decay, beta decay, positron emission or gamma emission are calculated. .

(part a) positron emission

(part b) beta decay

(part c) alpha decay

Step 1- Introduction (part a)

(part a)

${{}_{55}\mathrm{CS}}^{127}\to {{}_{54}\mathrm{X}}^{127}+{{}_{+1}\mathrm{e}}^0$

The radioisotope cesium $-127$ undergoes positron emission to form a stable nucleus of xenon for $127.$

Step 2 - Explanation (part b)

(part b)

${{}_{38}\mathrm{Sr}}^{90}\to {{}_{39}\mathrm{Y}}^{90}+{{}_{-1}\mathrm{e}}^0$

The radioisotope strontium $-90$ undergoes beta decay, forming a stable nucleus of $Y$.

$Y-90$

Step 3- calculation (part c)

(part c)

${{}_{85}\mathrm{At}}^{218}\to {{}_{83}\mathrm{Bi}}^{214}+{{}_2\mathrm{He}}^4$

The radioisotope astatine $218$ causes alpha decay and forms a stable bismuth nucleus.

$B i-214$