The answer is :
Nickel II carbonate octahydrate
The explanation:
-when Ni is the symbol of Nickel.
and CO3 is the symbol of carbonate group.
and both have 2 valence so, it will be write 2:2 = 1:1 → NiCO3 named Nickel caronae.
and any compound contain H2O will be named Hydrate and here we have 8 H2O so, i will e named octa (because of his 8 ) octahydrate
so, the compound will be Nickel II carbonate octahydrate