Which of the following selections completes the following nuclear reaction? a gamma ray plus 40 20 calcium becomes 39 20 calcium plus blank. a beta particle a neutron a positron an alpha particle gamma radiation

The Neutron ; ¹₀n

Explanation:

Let us have the equation;

Gamma ray + 40 20 Calcium ---> 39 20 calcium + blank

Rewriting our equation, we have;

⁰₀γ + ⁴⁰₂₀Ca → ³⁹₂₀Ca + A

We are to calculate what A is.

It is important to understand the following concepts;

Mass Number = Total number of Protons + Neutrons in an atom. It is usually represented by the superscript after the atom.

Atomic Number = Total number of Protons in an atom. It is usually represented by the subscript before the atom.

Total mass number;

Reactants = 0 + 40 = 40

Products = 39 + x

Total Atomic number;

Reactants = 0 + 20 = 20

Products = 20 + y

Since there have to be conservation of mass,

Reactant Mass Number = Product Mass Number

40 = 39 + x

x = 40 - 39 = 1

Reactant Atomic Number = Product Atomic Number

20 = 20 + y

y = 20 - 20 = 0

From our calculations we now know that A has atomic number of 0 and mass number of 1.

Only the Neutron fits this description.

The Neutron is; ¹₀n

Beta particle is ⁰₋₁e, Positron is  ⁰₁e, Gamma is ⁰₀γ and Helium is ⁴₂He