Structure and bonding GapFill

Electrons orbit regions around the nucleus which are referred to as  ionicmagneticrotationalelectronic orbitals. There are three types of these to be aware of:

1.  pdsf orbitals – spherical, symmetric about the centre, 1 orbital per subshell
2.  dpsf orbitals – dumb-bell-shaped, two lobes, 3 orbitals per subshell
3.  dpas orbitals – four-leaf clover (four lobes), plus a doughnut shape around the centre of 2 lobes for 1 orbital; 5 orbitals per subshell total

The order in which these orbitals are filled is determined by the  Chadwick modelAufbau principleDalton modelBohr model. This states that the orbitals with lower energies are filled before orbitals with higher energies. The order of subshells in terms of energy is:

 adps subshell <   spfd subshell <  dpsf subshell

The  DaltonRutherfordBohrplum pudding model of the atom states that electrons orbit the nucleus in quantised energy levels known as quantum states. These quantum states also have different amounts of energy associated with them, and this determines the order in which they are filled. The quantum state with the lowest amount of energy is the n =  01012 state as it is the closest to the nucleus and, therefore, has the greatest amount of  electrostatic attractionelectronegativityvan der Waals forcesintermolecular forces between the negative electrons and the positive protons. The next to be filled is the n =  1432 state, which is further away from the nucleus.