Question

Part C

Which element has the following configuration: [Ar]4s2?

Enter the chemical symbol for the element

Answer 1

Given the electronic configuration is : [Ar]4s²

In this there is Ar , the atomic number of Ar is 18.

There are 2 electrons in 4s orbital so the number of electrons in the given element is 18 (from Ar)+2 ( in 4s orbital )

                                                                                                                                      = 20 electrons

Therefore the element with atomic number 20 is Calcium .

Its chemical symbol is Ca