Question

question 12 (1 point)
in which period of the periodic table do the elements have a core - electron configuration that is the same as argon.
first
second
third
fourth
fifth

Explanation:

Argon (\(Ar\)) is in the third period. The core - electron configuration of an element is the electron configuration of the nearest noble gas with a lower atomic number. Elements in the fourth period have a core - electron configuration of \( [Ar] \). For example, potassium (\(K\)) has an electron configuration of \( [Ar]4s^{1}\), calcium (\(Ca\)) has \( [Ar]4s^{2}\) and so on.

Answer:

fourth