If the question is about Ni (without space), nickel metal, it can be NiO,
but the reaction to form it is not very likely, Ni is a rather precious metal.
BaBr2
aluminum oxide AlO3
K2S is the formula for the ionic compound formed from potassium and sulfur.
K2S is the formula for the ionic compound formed from potassium and sulfur.
The ionic compound formed between magnesium and chlorine has the formula MgCl2.
K2S is the formula for the ionic compound formed from potassium and sulfur.
The sodium ion is Na+ and the oxide ion is O2-. Therefore the ionic compound formed between the two ions has chemical formula Na2O which is sodium oxide.
The Formula Is mg3p2
This formula is SrS.
Cs2O
Al2S3====
The formula for the ionic compound barium chloride is BaCl2.