What balanced equation represents nuclear fusion?

Hint: A process that occurs as two or more atomic nuclei fuse to produce one or more new atomic nuclei and subatomic particles such as neutrons or protons is known as nuclear fusion. The disparity in mass between the reactants and components manifests itself as either energy release or absorption.

Complete answer:
To write an equation for such a reaction, we must first define certain fundamental rules which are given below:
The chemical symbol identifies each of the elements involved in the reaction.
The symbol is accompanied by two digits.
 The figure in the upper left corner is the mass number, also known as 'A.' The letter A represents the number of protons and neutrons that are contained in the nucleus.
The atomic number, or Z, is shown in the lower left corner. The Z identifies the class of atoms by describing the number of protons in the nucleus.
Here the symbols \[\alpha \]and $\beta $ are being used to represent the particles, where:
$\alpha = {}_2^4He$
$\beta = {}_{ - 1}^0e$
And the proton and neutron are given by:
 $proton = _1^1H$
$neutron = _0^1n$
In a balanced nuclear equation, the quantities of the superscripts and subscripts must be equal on both sides of the equation, similarly as they are in a balanced chemical equation.
Since the meaning of the symbols have been established, let us find out on how they can be extended to nuclear fusion. The fusion of two deuterium nuclei to form a tritium nucleus and a proton is a common example:
${}_1^2H + {}_1^2H \to {}_1^3H + {}_1^1H$
It must be observed that the superscripts on the reactants side and products side add up to $4$ . Similarly, the subscripts on the reactants side and products side add up to $2$ .

Note:
Given below are few more examples of nuclear fusion equations:
${}_1^2H + {}_2^3He \to {}_2^4He + {}_1^1H$
${}_2^3He + {}_2^3He \to {}_2^4He + 2{}_1^1H$
In all cases, the two reactant nuclei produce a compound of greater mass than one of them.