The name for Hg2NO3 is mercury(I) nitrate.
The compound name for Cd(OH)2 is cadmium hydroxide.
The compound name for Mg(NO3)2 is magnesium nitrate.
This compound is beryllium nitrate.
Cadmium (2) Carbonate
This compound is cadmium manganate.
The correct name of the compound Pb(NO3)2 is lead(II) nitrate.
The compound name for Hg2(NO3)2 is mercury(I) nitrate.
carbonate ion
The ionic compound name for Mg3(PO4)2 is magnesium phosphate.
The compound name of Pb(NO2)2 is lead(II) nitrite.
No compound has this formula. However, Ca(ClO4)2 is (with a lowercase L) is calcium perchlorate.