The element that has a valence configuration of 2s2 is

The element having given valence electronic configuration is beryllium.

Explanation:

Electronic configuration is defined as the representation of electrons around the nucleus of an atom. Number of electrons in an atom are determined by the atomic number of that atom.

Valence electrons are defined as the electrons present in the outermost shell of an atom.

We are given:

Valence electronic configuration of an atom =

So, the actual electronic configuration of atom will be

Total number of electrons = 2 + 2 = 4

So, the atomic number of given element is 4 and the element is beryllium

Hence, the element having given valence electronic configuration is beryllium.

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.