Explain why first ionisation energy decreases down a group.

As you go down the group, ionisation energy decreases because there are more electron shells and shielding increases, therefore the outer electron is further away from the positive nucleus and is less strongly attracted to it.

IA

Related Chemistry A Level answers

All answers ▸

Name and explain briefly the main stages of mass spectroscopy.


Describe how propenal, propanal and propanone can be distinguished from one another by simple chemical tests.


Why does iodine have a higher boiling point than chlorine?


For the equilibrium reaction PCl5(g) (equilibrium arrow)-> PCl3(g) + Cl2(g) explain the effect of increasing the concentration of Chlorine gas using the equilibrium constant.