why does copper show 2 valancies??
What do you mean shows 2 valencies?
"In chemistry, valence, also known as valency or valence number, is a measure of the number of bonds formed by an atom of a given element."
I guess Bipix means copper in its compounds can be either +1 or +2. Judging from the valence electrons, it should be +1 only.
Well.... There are Copper (III) and Copper (IV) as well...
Yes, but +1 and +2 are most common, on some levels on education they are the only ones mentioned.
Separate names with a comma.