Question

The specific charge of a proton is 9.6 × 10^7Ckg^-1. The specific charge of an alpha particle will be

Answer 1

An alpha particle is the nucleus of a He-4 atom and has two protons and two neutrons. Since only protons carry charge, the charge of an alpha particle will be twice the charge of a single proton. 

Charge on a single proton: +1.602x10^-19C 
Mass of proton: 1.67x10^-27 kg 
Net charge on a kilogram of protons: 
+1.602x10^-19C / 1.67x10^-27 kg = 9.58x10^7 C/kg 

Since an alpha particle has two protons, then the charge on the alpha is twice the charge on a proton. The mass of an alpha particle is essentially 4 times the mass of proton since the masses of protons and neutrons are very similar (p==1.0073 amu, n==1.0087 amu) 

Net charge on one kilogram of alpha particles: 
2(+1.602x10^-19C) / 4(1.67x10^-27 kg) = 4.79x10^7 C/kg

Answer 2

Answer:

The specific charge of an alpha particle will be $4.8\times10^{7}\ C kg^{-1}$

Explanation:

Given that,

Specific charge of proton = $9.6\times10^{7}\ Ckg^{-1}$

We know an alpha consists of two protons and two neutrons. the charge on the alpha is twice the charge on the proton.

The mass of an alpha particle will be four times the mass of proton.

We know the masses of protons and neutrons are approx similar.

Therefore,

The net charge presents on 1 kg alpha particle will be

$Specific\ charge =\dfrac{2\times1.6\times10^{-19}}{4\times1.67\times10^{-27}}$

$Specific\ charge=4.8\times10^{7}\ C kg^{-1}$

Hence, The specific charge of an alpha particle will be $4.8\times10^{7}\ C kg^{-1}$