Sentence Examples


  • POLYMETHYLENES, in chemistry, cyclic compounds, the simplest members of which are saturated hydrocarbons of general formula C 7, H 2nj where n may be r to 9, and known as tri-, tetra-, penta-, hexa-, and hepta-methylene, &c., or cyclo- propane, -butane, -pentane, -hexane, -heptane, &c.: - CH 21 CH 2 CH 2 CH2.CH2 CH2 CH2 CH2?C1H,, I I H ?
  • A somewhat related example is seen in the case of croconic acid, which is formed by the action of alkaline oxidizing agents on hexa-oxybenzene HO C C(OH): C(OH) HO C CO CO HO C CO 1 -* --j p_)CO HO.
  • Group VI.: 0, usually divalent, but tetravalent and possibly hexavalent in oxonium and other salts; S, Se, Te, di-, tetraand hexa-valent; Cr, di-, triand hexa-valent; Mo, W, di-, tri-, tetra-, pentaand hexa-valent.
  • Group VIII.: Fe, Co, divalent and trivalent; Ni, divalent; Os, Ru, hexavalent and octavalent; Pd, Pt, divalent and tetravalent; Ir, tri-, tetraand hexa-valent.
  • In the same way it may be shown that three tri-substitution, three tetra-substitution, one penta-substitution, and one hexa-substitution derivative are possible.