Question

During the fusion process, how is mass converted into energy?

Answer 1

`E = mc^2`

Explanation:

This is calculated using the famous equation of Einstein,

`E = m c^2`

In Fusion reaction like the ones taking place in the core of a Star, there is enough pressure to fuse hydrogen nuclei to form one helium nucleus.

So, 4 hydrogen nuclei are fused together to form one Helium nucleus. But, where does the energy come from that keeps the Sun from collapsing?.

When 4 Hydrogen nuclei are merged together they show a certain discrepancy in the mass when a Helium atom is formed, i.e the mass of 4 Hydrogen atoms before Fusion is higher than the mass of the Helium atom after the reaction this mass defect is converted into energy by `E = mc^2`.

`"mass of a hydrogen atom " = " 1.00794 u"`

`"mass of one helium atom " = " 4.002602 u"`

Where `u = 1.6605 xx 10^(-27)"kg"`.

The mass defect, `Deltam`, will be

`Delta m = 4 xx m_H - m_(He)`

`= 4 xx "1.00794 u" - "4.002602 u"`

`= "0.029158 u "` or `" "4.8416859 * 10^(-29)"kg"`

In the equation `E = mc^2`, `c` is the speed of light in a vacuum, approximately equal to `3 * 10^8"m s"^(-1)`.

This means that you have

`E = 4.8416859 * 10^(-29)"kg" * (3 * 10^8)^2"m"^2"s"^(-2)`

`E = 4.35751731 * 10^(-12)" J per reaction"`