Could someone please help me solve number 6.
If you do more it would be appreciated:)

  ¹₀e

Explanation:

Nuclear reaction:

           ²⁷₁₃Al          +        ⁴₂He          →         ³⁰₁₅P   +    ?

Problem is to balance the nuclear equation:

In balancing nuclear reactions, there is conservation of mass numbers and atomic numbers, i.e. the sum of mass numbers(superscript) on the product side must be equal to the sum of the mass numbers on the reactant side.

The sum of the atomic numbers(subscript) on the product side must be equal to the sum of the atomic numbers on the reactant side.

            ²⁷₁₃Al          +        ⁴₂He          →         ³⁰₁₅P   +    ₐⁿX

for the mass numbers:

             27 + 4  = 30 + n

                 31 - 30 = n

                      n = 1

for the atomic numbers;

             13 + 2 = 15 + a

                a = 15 - 15

                a = 0

The specie is ¹₀X

This unknown specie X is indeed a positron.

                       ¹₀e