An element X has the proton number 18. The next element in the periodic table is an element Y.
Which statement is correct?

This question is incomplete

Explanation:

This question is incomplete. However, the element X with the atomic number of 18 is Argon (Ar) while the next element (element Y) in the periodic table, with atomic number 19, is potassium (K).

Element X is found in the group zero (also called group 18 and elements found therewith are referred to as noble gases) of the periodic table while element Y is found in group 1 (elements found here are referred to as alkali metals).

Element X has a completely filled outermost shell while element Y has one electron in its outermost shell.

Element X is a metal while element Y is a nonmetal.