If element x has 19 protons, how many electrons does it have?

Element has will have 19 electrons.

The atom comprises of three sub-atomic particles namely protons, electrons and neutrons. The protons are positively charged, electron is negatively charged and neutron is null charged. For all atoms acting as component of elements the following rules applies:

From the above rules, it can be inferred that as the number of protons and electrons are same, as element X as 19 protons, it will have 19 electrons.