Which element have the following electron configuration 1s2 2s2 2p6 3s1?

Answer 1

It is the electronconfiguration of elemental Sulfur with 16 electrons:

Explained:

1s2 2s2 2p6 3s23p4 => add up the superscripts (bold): 2+2+6+2+4 = 16

16 electrons means 16 protons for that element, so it is atom number 16 in the Periodic Table: 3rd period (3 electron levels: 1, 2, 3) with 6 electrons (3s23p4) in it, so the element is in group 6 (or 16).

Answer 2

Assuming the atom is neutral, the atomic number is equal in magnitude to the number of electrons, which is 22. This element is titanium, which has an atomic number of 22.

Answer 3

The atomic number is 20.

Answer 4

That is sodium, atomic number 11.

Answer 5

This element is calcium (Ca).