Which compound contains a transition metal?

The compound that contains a transition metal is indeed iron(II) sulfate, represented by FeSO4. Transition metals are the elements found in groups 3 to 12 of the periodic table, and they are characterized by their ability to form variable oxidation states and colored compounds. Iron (Fe) is a well-known transition metal, and in the case of FeSO4, it specifically has an oxidation state of +2.

In addition to containing the transition metal iron, FeSO4 is also notable for its applications, such as in the treatment of iron deficiency anemia, where iron is required for hemoglobin production.

The other listed compounds do not contain transition metals. Magnesium oxide, MgO, comprises magnesium (an alkaline earth metal) and oxygen, while NaBr consists of sodium (also an alkaline metal) and bromine. The option stating that no compound contains a transition metal is incorrect as FeSO4 clearly includes iron as a transition element. Understanding these definitions and characteristics of transition metals is key in identifying and categorizing compounds in chemistry.