Is the charge of hydrogen carbonate/ bicarbonate - or 2- ?

Question

My book says its - yet my teacher says its 2-. I also have another discrepancy. My teacher says that Copper could form anions of Cl- and Cu 2-. How could copper form a chlorine anion? Isnt it that copper could only form Cu- and Cu 2-?

Also, my teacher says that cesium forms anions of -1. I thought that cesium forms +1 cations? Am I right or is my teacher crazy?

Answer 1

Bicarbonate (HC03) is -1
Carbonate CO3 is -2

Copper forms Cu+1 and Cu+2 oxidation states

Cl- was probably a typo of Cu1- (which is also wrong anyway)

Cesium forms +1 ions (at least in my book)

Answer 2

correct anions and cations:

CO3 2-
HCO3 -
Cu+
Cu2+
Cl-
Cs+

Answer 3

carbonate is -2 ----- CO3
bicarbonate -1 ----------- HCO3

Cu+
Cu++