Question

Which principle lays the condition for an electron to occupy an orbit in an atom?

Answer 1

Filling of the electron in orbitals

• It is a universal truth that the lowest energy state of matter is the most stable.
• Orbits are the well-defined circular paths around the nucleus in which the electrons revolve.
• There are four types of orbitals: $s,p,d,$ and $f$.
• Electrons in an atom can be found in any of the atom's many orbitals.
• Since the energy of orbitals varies, electrons in various orbitals will have varying energies.

Aufbau principle

• The Aufbau principle describes how the atomic orbitals of an atom are filled with electrons in its ground state.
• According to the principle, electrons are filled into atomic orbitals in an increasing sequence of orbital energy.
• The Aufbau principle states that atomic orbitals that are available and have the lowest energy levels get filled before those that have higher energy levels.
• The increasing order of orbital energy is as follows: