问答题 Which main group elements form monatomic ions in their compounds? (b) Give the charge on these ions,as a function of the periodic group.

【正确答案】(a) Groups I, II, m, V, VI and VII of the main groups form monatomie ions. (b) The charge are, respectively, 1 +, 2 +, 3 +, 3 -, 2 -, and 1 -. Example are Na⁺ , Mg²⁺ , Al³⁺ , p^3-, S^2-, and Cl^- . The heaviest elements of group IV form 4+or 2+ions,such as Pb⁴⁺ and Pb²⁺.

【答案解析】