Magnesium atoms have two electrons in the outermost shell and chlorine atoms have seven. The compound magnesium chloride would contain
A) 1 magnesium and 1 chlorine.
B) 1 magnesium and 2 chlorine.
C) 2 magnesium and 1 chlorine.
D) 2 magnesium and 7 chlorine.
E) impossible to tell without more information

Question

Quizplus · Accepted Answer

Magnesium wants to lose its two outermost electrons to achieve a stable electron configuration (full outer shell), while chlorine wants to gain one electron to achieve the same. By bonding, magnesium will donate its two electrons to chlorine, resulting in the formation of magnesium chloride. Each magnesium atom can bond with two chlorine atoms, giving the compound a 1:2 magnesium-to-chlorine ratio, which corresponds to choice B.

Magnesium Atoms Have Two Electrons in the Outermost Shell and Chlorine