Question

How many protons are in the nucleus of an atom that has an atomic number of 23 and a mass number of 51?

Answer 1

If the atomic number is 23, then you know (i) the number of protons in the nucleus; and (ii) the identity of the element.

Explanation:

`Z`, the atomic number, is the number of positive particles, protons, present in the nucleus. The number determines elemental identity. If we look at the Periodic Table, we see the listed atomic numbers, and find that the atom is vanadium, which commonly has a mass number of 51.

How many electrons does a neutral vanadium atom have?