BeO+2HCl→BeCl2+H2O and BeO+2NaOH+H2O→Na2[Be(OH)4](Sodium beryllate) BeO is an amphoteric oxide as it reacts with an acid as well as a base. As the atoms get larger, the ionization energy decreases and the elements also become more basic. BeO is insoluble in water but dissolves in acids to give salts, and in alkalis to give beryllates which on standing precipitate as the hydroxide.