Question

Which of the following is the approximate energy equivalent of the mass of an $\alpha$ - particle?

• A. $1877\text{MeV}$
• B. $2396\text{MeV}$
• C. $3755\text{MeV}$
• D. $4840\text{MeV}$

Answer 1

The correct option is C $3755\text{MeV}$

An $\alpha$ - particle is a helium nucleus which consists of two protons and two neutrons.
A single proton's mass is equivalent to an energy of $938.3\text{MeV}$ and that of a single neutron is $939\text{MeV}$.
So, the energy equivalent to the mass of an $\alpha$ - particle is:

$E=2\times (938.3+939)\text{MeV}$
$E=2\times 1877.3\text{MeV}$
$E=3754.6MeV\approx 3755\text{MeV}$