Final answer:
The electron configuration [Ar]4s² represents the element calcium (Ca), which is an alkaline earth metal with two valence electrons in the 4s orbital. Option C is correct.
Step-by-step explanation:
The element represented by the electron configuration [Ar]4s² is calcium (Ca). The notation [Ar] indicates that the element has the same number of electrons as argon in its inner shells, which are the core electrons.
The '4s²' part shows that there are two electrons in the 4s orbital, which are the valence electrons for the element. Looking at the periodic table, calcium is the only element that fits this description, as it is an alkaline earth metal located in Group 2 and Period 4 with atomic number 20.
The electron configuration [Ar]^482 represents the element Calcium (Ca).
The electron configuration [Ar] refers to the noble gas Argon, which has 18 electrons. The superscript 4 indicates that the 4th energy level (n=4) is occupied by electrons. The s orbital can hold a maximum of 2 electrons, so the 8 in the superscript refers to the number of electrons in the 4s orbital. Therefore, the complete electron configuration for Calcium is [Ar]4s².