Question

The increasing order for the values of $e/m$ (charge/mass) for electron ($e$), proton ($p$), neutron ($n$) and alpha particle ($\alpha$) is:

• A. $e,p,n,\alpha$
• B. $n,p,e,\alpha$
• C. $n,p,\alpha ,e$
• D. $n,\alpha ,p,e$

Answer 1

The correct option is D $n,\alpha ,p,e$

For neutron $\left(n\right),\frac{e}{m}=0$

For proton $\left(p\right)=\frac{e}{m}\times =\frac{1}{1}=1$

$Forelectron,\left(e^{-}\right),\frac{e}{m}=\frac{1}{1/1837}=1837$

For alpha particle $\left(\alpha \right),\frac{e}{m}=\frac{2}{4}=0.5$

The increasing order for the values of $\frac{e}{m}$ is $n,\alpha ,p,e$.

Hence, the correct option is $\text{D}$.