Question

When magnesium combines with sulfur to form magnesium sulfide, it is oxidized to Mg2+. Which statement is true about this reaction?
A. 

It involves gain of electrons.

B. 

It involves loss of electrons.

C. 

It involves loss of oxygen.

D. 

It involves gain of hydrogen.

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Answer 1

Answer;

B. It involves loss of electrons.

Explanation;

• Oxidation occurs when electrons are lost by an atom while reduction refers to the gain of electrons by an atom.
• In this case, magnesium atom reacts with sulfur to form magnesium sulfide by loosing two electrons and forming magnesium ion (Mg2+). Therefore magnesium undergoes oxidation.
• Sulfur, on the other hand will gain electrons to form Sulfide ions, therefore it undergoes reduction.
• Therefore; In magnesium sulfide (MgS), magnesium loses two electrons and becomes a cation with a positive-two charge. Likewise, sulfur obtains the two electrons lost from magnesium and becomes an anion with a negative-two charge. However, the overall charge of MgS is zero.