Why ionization enthalpy Berrelyium is greater …

first understand what is ionization enthalpy : this enthalpy sometimes called ionization enegy, it suggest that amount of enegy is required to convert atom into ion or removal of electron from its outermost shell.

now we have to find electronic configuration of beryllium and boron , beryllium has 2 electrons in its outer most s-subshell, whereas boron has 2 electrons in s-subshell and 1 electron in 2p orbital , now we know that electron repels  each other so 2s orbital of Böron apply repulsive force on 2p orbital so they easily comes out ,but berylium has 2 electrons at 2s orbital , in this state both electrons of 2s orbital are moving in opposite direction so they can not apply any repulsive force on each other hence to remove an electron we have to supply total amont of energy.

i hope u understand, if not please send me email on [email protected]   so i can show u it by presentation.