Question

which statement best explains why magnesium and chlorine combine in a 1:2 ratio? (1 point)
o chlorine can accept twice as many electrons as magnesium has in its outer shell.
o magnesium has one electron shell, and chlorine has two electron shells.
o magnesium has two valence electrons, and chlorine can accept one electron in its outer shell.

Explanation:

• Magnesium (\(Mg\)) has two valence electrons. It tends to lose these two electrons to achieve a stable electron configuration.
• Chlorine (\(Cl\)) has seven valence electrons and needs one more electron to complete its outer shell (octet rule).
• So, one magnesium atom can provide two electrons, and each chlorine atom can accept one electron. Therefore, one magnesium atom combines with two chlorine atoms (\(1:2\) ratio) to form \(MgCl_2\).

• The first option is incorrect because it's about the transfer of electrons (not just the number of electrons chlorine can accept compared to magnesium's outer - shell electrons in a non - transfer context).
• The second option about the number of electron shells is not relevant to the \(1:2\) ratio in compound formation.

Answer:

Magnesium has two valence electrons, and chlorine can accept one electron in its outer shell.