why Ga has lower atomic radius than Al ?
Electronic configuration of Ga includes d-orbital which has a poor shielding effect.
When we move from Aluminium to Gallium,18 electrons are added.
2 electrons go into s-subshell(good shielding)
6 electrons go into p-subshell(good shielding)
10 electrons go into d-subshell(poor shielding)
Those last 10 electrons help to increase effective nuclear charge and subsequently decrease size of atom.
When we move from Aluminium to Gallium,18 electrons are added.
2 electrons go into s-subshell(good shielding)
6 electrons go into p-subshell(good shielding)
10 electrons go into d-subshell(poor shielding)
Those last 10 electrons help to increase effective nuclear charge and subsequently decrease size of atom.