Question

$\mathrm{NaCl}$ molecule is made of which of the following ions?

• A. ${\mathrm{Na}}^{+}$ and ${\mathrm{Cl}}^{-}$
• B. ${\mathrm{Na}}^{-}$and ${\mathrm{Cl}}^{+}$
• C. ${\mathrm{Na}}^{-}$ and ${\mathrm{C}}^{+}$
• D. ${\mathrm{Na}}^{+}$ and ${\mathrm{C}}^{-}$

Answer 1

The correct option is A

${\mathrm{Na}}^{+}$ and ${\mathrm{Cl}}^{-}$

Explanation for Correct Answer:

Option (A) ${\mathrm{Na}}^{+}$ and ${\mathrm{Cl}}^{-}$

• Sodium chloride $\left(\mathrm{NaCl}\right)$ is an ionic compound
• One molecule of Sodium chloride is composed of one Sodium ($\mathrm{Na}$) atom and one Chlorine ($\mathrm{Cl}$) atom as indicated by the chemical formula.
• The atomic number of Sodium($\mathrm{Na}$) is 11 and the electronic configuration can be written as $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^1$
• The atomic number of Chlorine($\mathrm{Cl}$) is 17 and the electronic configuration can be written as $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^5$
• Here, Chlorine needs one more electron to complete its outermost shell
• Thus, Sodium donates one electron and gets a positive charge, and Chlorine accepts that electron and gets a negative charge

• $\mathrm{NaCl}$ is water-soluble and it forms Sodium cation and Chloride anion.
• The sodium and chloride ions are present in the ratio of $1:1$
• Hence option (A) is correct

Explanation for incorrect Answers:

Option (B) ${\mathrm{Na}}^{-}$and ${\mathrm{Cl}}^{+}$

• In $\mathrm{NaCl}$ molecule, Sodium donates one electron and gets a positive charge to form ${\mathrm{Na}}^{+}$, and Chlorine accepts that electron and gets a negative charge to form ${\mathrm{Cl}}^{-}$.
• Hence incorrect option.

Option (C) ${\mathrm{Na}}^{-}$ and ${\mathrm{C}}^{+}$

• $\mathrm{NaCl}$ molecules contain Sodium and Chlorine ions.
• Hence incorrect option.

Option (D) ${\mathrm{Na}}^{+}$ and ${\mathrm{C}}^{-}$

• $\mathrm{NaCl}$ molecules does not contains carbon molecules.
• Hence incorrect option.

Therefore, option (A) ${\mathrm{Na}}^{+}$ and ${\mathrm{Cl}}^{-}$is the correct answer.