Concept:Only metals above hydrogen in the reactivity series can replace hydrogen from water or steam.
Metals below hydrogen are less reactive and cannot do so.
Explanation:The reactivity series arranges metals in order of their ability to lose electrons.
Highly reactive metals like sodium react vigorously with cold water.
Magnesium and iron react with steam when heated.
Copper is placed below hydrogen in the reactivity series.
Since copper is less reactive than hydrogen, it cannot displace hydrogen from
H2O or steam.
Therefore, among sodium, magnesium, iron, and copper, copper is the metal that cannot replace hydrogen.
Answer:Copper cannot replace hydrogen from water or steam.
Correct option: D.