Page 12 - classification of elements
P. 12
Some elements with variable valencies
Name of elements Symbols Valency
Iron Fe 2 or 3
Copper Cu 1 or 2
Silver Ag 1 or 2
Gold Au 1 or 3
Lead Pb 2 or 4
Mercury Hg 1 or 2
Duplet: The state of having two electron in the
outermost k shell is called duplet.
Octet: The state of having 8 electrons in the
outermost shell except k shell as outermost is called
octet.
