I have mocks in weeks and our teacher just left for maternity leave without finishing the syllabus! Thanks so much for the helpful videos, May God bless you.
shielding is basically the full shell of inner electrons preventing the outer electrons from feeling the nuclear charge(pos charge and neg charge attract).The greater shielding of outer e- by full inner shells-less attractive force between the nucleus and the outer e-> this giving a lower IE to be used.
