How is nitrogen-14 an anion?

Since it has 7 protons, neutrons, and electrons, wouldn't it not be an anion since it does not have a negative electric charge?

Oct 20, 2017

An atom of nitrogen-14 is not an anion.

Explanation:

First and foremost, if an atom has equal numbers of protons inside the nucleus and of electrons surrounding the nucleus, then it is electrically neutral, i.e. it is neither a cation nor an anion.

In order for an atom to be an anion, it must have more electrons surrounding the nucleus than protons inside the nucleus.

You know that

$\text{net charge" = "no. of protons " - " no. of electrons}$

This shows that equal numbers of protons and electrons correspond to a net charge of $0$, i.e. the atom is neutral.

If you have

$\text{no. of electrons " > " no. of protons}$

then you get

$\text{net charge} < 0$

In this case, the atom is an anion because it carries a negative net charge.

Also, keep in mind that the identity of the isotope is irrelevant when it comes to the net charge of the atom.

In this case, nitrogen-14 denotes the isotope of nitrogen that has $7$ protons and $7$ neutrons inside the nucleus. But since the number of neutrons does not influence the net charge of the atom, it is irrelevant in this regard.

In order for nitrogen-14, $\text{^14"N}$, to be an anion, it must have $7$ protons and $7$ neutrons inside the nucleus and $10$ electrons surrounding the nucleus.

In this case, you have

$\text{net charge} = 7 - 10 = - 3$

which means that the anion carries a $3 -$ net charge. The symbol for a nitrogen-14 anion will be

${\text{^14"N}}^{3 -}$

As a final note, don't forget to review the difference between neutral atoms, cations, and anions.