Complex sentence: Consequently very little of the chemistry of nitrogen is that of simple ions and nearly all its compounds are covalent, whereas oxygen (with an electronegativity surpassed only by F) and the rest of the halogens readily form simple ions and ionic compounds.
Split into simpler sentences: Consequently very little of the chemistry of nitrogen is that of simple ions and nearly all its compounds are covalent. Whereas oxygen (with an electronegativity surpassed only by F) and the rest of the halogens readily form simple ions and ionic compounds.