Sc,y,lu which has high inonization enthalpy

I.E of Sc>Y>La Down the group size increases as number of shells increases. so force of attraction of nucleus on outermost electrons decreases and hence less energy is required to ...

For IIIB group IP decrease from down the group as Sc > Y > La IP is inversely proportional to size so down the group it decrease. but for d block elements (except IIIB) 3d >4d <...

helium has the largest first ionization energy, while francium has one of the lowest.