Beryllium, like lithium, forms a protective oxide layer in the air, so it is stable even when it is red hot in the air. Insoluble in cold water, slightly soluble in hot water, soluble in dilute hydrochloric acid, dilute sulfuric acid and potassium hydroxide solution to release hydrogen. Metal beryllium has significant corrosion resistance to oxygen-free sodium metal even at higher temperatures. Beryllium is in the +2 valence state and can form polymers as well as a class of covalent compounds with significant thermal stability. Anomalous Properties Of Beryllium The valence electron shell structure of Be atom is 2s2, its atomic radius is 89pm, the Be2+ ionic radius is 31pm, Read more