Question

The nuclear equation is incomplete. Superscript 1 Subscript 1 Baseline H + Superscript 15 Subscript 7 Baseline N yields blank + Superscript 4 Subscript 2 Baseline H e What particle completes the equation? Superscript 12 Subscript 6 Baseline M g Superscript 11 Subscript 5 Baseline B Superscript 11 Subscript 5 Baseline N a Superscript 12 Subscript 6 Baseline C

Answer 1

The missing species is carbon-12
`^(12)_{\phantom{1}6}\mathrm{C}`.

The nuclear equation should be
`^(1)_(1)\mathrm{H} + ^(15)_{\phantom{1}7}\mathrm{N} \to ^(12)_{\phantom{1}6}\mathrm{C} + ^(1)_(1)\mathrm{H}`.

Step-by-step explanation:

Let
`A` represent the mass number of the missing species, and let
`Z` represent its atomic number.

`^{\;\;\;\text{Mass number $\to$ $A$}}_{\text{Atomic number $\to$ $Z$}}\mathrm{X}`.

For this question, there are three things to consider:

• The sum of the mass numbers should be conserved.
• Since there's no beta particle (
  `\rm e^(-)` or
  `\mathrm{e}^(+)`) involved, the sum of the atomic numbers should also be conserved.
• The atomic number of the missing species should correspond to atomic symbol.

Mass Number

The sum of the mass numbers on the left-hand side of this reaction is:
`1 + 15 = 16`.

The sum of the mass number on the right-hand side (including that of the missing species) is
`(A + 4)`.

These two numbers should be the same. In other words,
`A + 4 = 16`. Therefore, the mass number of the missing species would be
`12`.

Atomic Number

The sum of the atomic numbers on the left-hand side of this reaction is:
`1+ 7 = 8`.

The sum of the mass number on the right-hand side (including that of the missing species) is
`(Z + 2)`.

These two numbers should be the same. In other words,
`Z + 2 = 8`. Therefore, the mass number of the missing species would be
`6`.

Symbol

The atomic number
`Z` of the missing species is
`6`. Look up a modern periodic table. The element with atomic number