Answer:
The missing species is carbon-12 [tex]^{12}_{\phantom{1}6}\mathrm{C}[/tex].
The nuclear equation should be [tex]^{1}_{1}\mathrm{H} + ^{15}_{\phantom{1}7}\mathrm{N} \to ^{12}_{\phantom{1}6}\mathrm{C} + ^{1}_{1}\mathrm{H}[/tex].
Explanation:
Let [tex]A[/tex] represent the mass number of the missing species, and let [tex]Z[/tex] represent its atomic number.
[tex]^{\;\;\;\text{Mass number $\to$ $A$}}_{\text{Atomic number $\to$ $Z$}}\mathrm{X}[/tex].
For this question, there are three things to consider:
The sum of the mass numbers on the left-hand side of this reaction is: [tex]1 + 15 = 16[/tex].
The sum of the mass number on the right-hand side (including that of the missing species) is [tex](A + 4)[/tex].
These two numbers should be the same. In other words, [tex]A + 4 = 16[/tex]. Therefore, the mass number of the missing species would be [tex]12[/tex].
The sum of the atomic numbers on the left-hand side of this reaction is: [tex]1+ 7 = 8[/tex].
The sum of the mass number on the right-hand side (including that of the missing species) is [tex](Z + 2)[/tex].
These two numbers should be the same. In other words, [tex]Z + 2 = 8[/tex]. Therefore, the mass number of the missing species would be [tex]6[/tex].
The atomic number [tex]Z[/tex] of the missing species is [tex]6[/tex]. Look up a modern periodic table. The element with atomic number
