Question

Using the aufbau principle write the ground state electronic configuration of boron (z=5)

Answer 1

$\boxed{\bf{\red{Aufbau\:principle:}}}$

• In the ground state of the atoms, the orbitals are filled in order to their increasing energies.
• 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s....

✴ Electronic configuration of Boron

$\underline{\boxed{\bf{\purple{B(Z=5) : 1s^2\:2s^2\:2p^1}}}}$

⏭ Pauli exclusion principle : No two electrons in an atom can have the same set of four quantum numbers. It can also be stated as : "only two electrons may exist in the same orbital and these electrons must have opposite spin."

⏭ Hund's rule of maximum multiplicity : Pairing of electrons in the orbitals belonging to the same subshell does not take place until each orbital belonging to that subshell has got one electron each.