As one proceeds from oxygen to polonium in Group 16 (VIA) of the Periodic Table, the number of valence electrons
for each succeeding element

The bergeron process.

First adhesives: hide glue.  which is made by boiling raw hides and bones or fish skins and bladders.other first adhesives: asphalt/tar, pitch/plant sap, and even blood.hope that : )

For apex it is hydroxyl