Explain why the first ionisation energy of Al is less than that of Mg?
The outer electron on aluminium is removed from the 3p sub-level, whereas the outer electron on magnesium is removed from the 3s sub-level.The 3p sub-level is higher in energy than the 3s sub-level.Aluminium's outer electron is further away from the nucleus and less attracted to the nucleus.This means less energy is needed to remove the electron from aluminium.
Related Chemistry A Level answers
All answers ▸Define the term 'first ionisation energy' and explain why the first ionisation energy shows a general increase across period 2
How do you go about answering titration equations?
Explain why hydrogen bonding occurs between water molecules
In the reaction CO(g) + 2H2(g) <--> CH3OH(g), explain why an increase in pressure increases the yield of methanol