Question

what is the correct electron dot formula for sodium chloride?\
\
\\(\boldsymbol{\circ\\ \left\

$$\begin{array}{c}\ \\text{na}\ \\end{array}$$

\
ight^+\\ \\:\left\

$$\begin{array}{c}\ \\text{cl}\ \\end{array}$$

\
ight^-}\\)\
\
\\(\boldsymbol{\circ\\ \left\

$$\begin{array}{c}\ \\text{na}\ \\end{array}$$

\
ight^+\\ \\ \left\

$$\begin{array}{c}\ \\text{cl}\ \\end{array}$$

\
ight^-}\\) (with electron dots around cl)\
\
\\(\boldsymbol{\circ\\ \left\

$$\begin{array}{c}\ \\text{na}\ \\end{array}$$

\
ight^+\\ \\ \left\

$$\begin{array}{c}\ \\text{cl}\ \\end{array}$$

\
ight^-}\\) (with electron dots around na)\
\
\\(\boldsymbol{\circ\\ \left\

$$\begin{array}{c}\ \\text{na}\ \\end{array}$$

\
ight^+\\ \\ \left\

$$\begin{array}{c}\ \\text{cl}\ \\end{array}$$

\
ight^-}\\) (with electron dots around both na and cl))

Explanation:

Sodium chloride is an ionic compound. Sodium (Na) has 1 valence electron, which it loses to form a $\text{Na}^+$ ion with no remaining valence electrons. Chlorine (Cl) has 7 valence electrons; it gains 1 electron to form a $\text{Cl}^-$ ion with a full octet (8 valence electrons). The electron dot structure shows the charged ions separately, with the chloride ion having 8 dots around it.

Answer:

$\boldsymbol{[Na]^+ \ [:\ddot{Cl}:]^-}$ (the second option)