As Al+3 has noble gas configuration. the IE3 of Al is very low As Li has 3 e- only. Li+3 will be having no e-.hence a higgh amount of energy is needed. lowest= al highest=Li Solution As Al+3 has noble gas configuration. the IE3 of Al is very low As Li has 3 e- only. Li+3 will be having no e-.hence a higgh amount of energy is needed. lowest= al highest=Li.