The first ionization of Beryllium is greater than that of Boron because beryllium has a stable complete electronic configuration(1s2 2s2)so it requires more energy to remove the first electron from it......whereas boron has the electronic configuration(1s2 2s2 3s1)which needs lesser energy than that of beryllium to remove the valence electron.

이유는 Be는 complete electron configuration 을 가지고 있고 Boron은 3s 에 unpaired electron을 가지고 있어서 electron을 orbital로 부터 remove하기 조금더 쉬워서 그렇답니다.