Question

Write the electronic orbital configuration for atom of element having atomic number 20

Answer 1

Answer:

1s2 2s2 2p6 3s2 3p6 4s2

Explanation:

The atomic number is 20, and the electron will fill the manner shown in the picture.

The electronic configuration will be 1s2 2s2 2p6 3s2 3p6 4s2

s orbitals can have 2 electrons at maximum

and p orbitals can have 6 electrons at maximum

And as the picture shows 4s orbital will be filled before 3d orbital.

As there is no electron left to be filled after 4s orbital, 3d will be vacant.