Which compound contains a transition metal?

The compound that contains a transition metal is iron(II) sulfate, represented as FeSO4. Transition metals are defined as elements that have partially filled d-orbitals and include metals found in the d-block of the periodic table, specifically groups 3 to 12.

In this case, the presence of iron (Fe) in FeSO4 classifies it as a transition metal because iron is located in the d-block of the periodic table. It can exhibit multiple oxidation states, which is a characteristic of transition metals, further demonstrating its classification.

The other listed compounds comprise elements that do not belong to the transition metal category. Magnesium oxide (MgO) contains magnesium, which is an alkaline earth metal, sodium bromide (NaBr) contains sodium, which is an alkali metal, and the option stating that no compound contains a transition metal eliminates any possibility of including compounds with d-block elements altogether. Thus, FeSO4 is the only correct choice here.