Question

do the number of protons always equal the number of neutrons?
if given the atomic # of an element, what two other pieces of information do you also know?

Explanation:

First Question: Do the number of protons always equal the number of neutrons?

In an atom, the number of protons (atomic number) doesn't always equal the number of neutrons. For example, in hydrogen - 1, there is 1 proton and 0 neutrons; in carbon - 12, protons (6) equal neutrons (6), but in carbon - 14, there are 6 protons and 8 neutrons. So the number of protons and neutrons can be different.

The atomic number (\(Z\)) of an element is equal to the number of protons in the nucleus of an atom of that element. Also, in a neutral atom, the number of electrons is equal to the number of protons (since the atom is electrically neutral, the positive charge from protons is balanced by the negative charge from electrons). So if we know the atomic number, we know the number of protons and (for a neutral atom) the number of electrons.

Answer:

No, the number of protons does not always equal the number of neutrons.

Second Question: If given the atomic # of an element, what two other pieces of information do you also know?