Question

what changes occur in the energy of ionization of the element on moving left to right across a period for 2 marks

Answer 1

Ionization Energies increase going left to right across a period and increase going up a group. As you go up a group, the ionization energy increases, because there are less electron shielding the outer electrons from the pull of the nucleus

Answer 2

Ionization energy generally increases moving from left to right across an element period (row). This is because the atomic radius generally decreases moving across a period, so there is a greater effective attraction between the negatively charged electrons and positively-charged nucleus.