pentavalent, a. Chem.
(pɛnˈtævələnt)
[f. penta- + L. valēnt-em having power or value.]
Having the combining power of five atoms of hydrogen or other univalent element; quinquivalent.
| 1871 Roscoe Elem. Chem. 174 The elements of the nitrogen group possess a peculiarity by which they frequently appear as if they were pentavalent. 1881 A. W. Williamson in Nature XXIV. 418/1 An atom of nitrogen or of antimony is only known to be trivalent in combination with hydrogen; but each of them occurs in form of a pentavalent compound with chlorine. |