Question

list of elements having valency 1 to 20 with symbol and name serially

Answer 1

Monovalent H Cl Br I Na K Cu(I) Ag Au(I) Divalent O S Mg Ca Ba Zn Pb Cu(ii) Fe(ii) Sn(ii) Trivalent Boron N P(iii) Al Fe(iii) Au(iii) Tetravalent C Si S(iv) Sn(iv) Pentavalent P(v) Hexavalent S(vi)