Question

What is the electron configuration for La?

Answer 1

Answer: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f1

How To Find:

All you have do is

1. List all the orbitals in the increasing order of their energies
2. Fill them with appropriate number of electrons.(for eg: 1s orbital has max. 2 electrons , 2p orbitals has maximum 6 electrons....)
3. Since the atomic number of Lanthanum is 57 , ensure you have that much electrons in these orbitals.