Question

Which of the following is stated by Aufbau Principle?

• A. No two electrons in an atom can have same set of quantum numbers
• B. The maximum number of electrons in the shell with principal quantum number 'n' is equal to 2n
• C. In the ground state of the atoms, the orbitals are filled in order of their increasing energies
• D. None of the above

Answer 1

The correct option is C

In the ground state of the atoms, the orbitals are filled in order of their increasing energies

In the ground state of the atoms, the orbitals are filled in order of their increasing energies. In other words, electrons first occupy the lowest energy orbital available to them and enter into higher energy orbitals only after the lower energy orbitals are filled.

The order in which the energies of the orbitals increase and hence the order in which the orbitals are filled is as follows:

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s.....