A deuterium reaction that occurs in an experimental fusion reactor is in two stage:
(A) Two deuterium `(._1^2D)` nuclei fuse together to form a tritium nucleus, with a proton as a by product written as `D(D,p)T`.
(B) A tritium nucleus fuses with another deuterium nucleus to form a helium `._2^4He` nucleus with neutron as a by - product, written as T (D,n) `._2^4He`.
Compute (a) the energy released in each of the two stages, (b) the energy released in the combined reaction per deutrium. (c ) What percentage of the mass energy of the initial deuterium is released. Given,
`{:(._1^2D=2.014102 am u),(._1^3 T=3.016049), (._2^4 He =4.002603 am u),(._1^1 H =1.007825 am u),(._0^1 n =1.00665 am u):}`.

Explanation

To solve the problem step by step, we will compute the energy released in each of the two stages of the deuterium fusion reaction, the total energy released per deuterium nucleus, and the percentage of mass energy released.

### Step 1: Calculate the energy released in the first reaction (D + D → T + p)

**Reaction:**
\[ D + D \rightarrow T + p \]

**Masses involved:**
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