Give the chemical formula of the following hydrated ionic substance: nickel (II) phosphate octahydrate.

• A. NiPO₄ • 8 H₂O
• B. Ni₃(PO₄)2 • 7 H₂O
• C. Ni₃(PO₄)2 • 8 H₂O
• D. Ni₂(PO₄)₃ • 8 H₂O
• E. Ni₂(PO₄)₃ • 7 H₂O

Answer: (C)