Predict the empirical formula of the ionic compound that forms from sodium and fluorine.

              NaF

Explanation:
                   Electronic configuration of Sodium is as follow,

                                      Na  =  11  = 1s², 2s², 2p⁶, 3s¹

As shown in electronic configuration, Sodium has 1 valence electrons in its valence shell. Therefore, to complete its noble gas configuration it donates one electron form Na⁺.

                                     Na⁺  =  1s², 2s², 2p⁶

                   Electronic configuration of Fluorine is as follow,

                                      F  =  9  = 1s², 2s², 2p⁵

As shown in electronic configuration, fluorine has 7 valence electrons in its valence shell. Therefore, to complete its noble gas configuration it accepts one electron from Na to form F⁻.

                                      F⁻ = 1s², 2s², 2p⁶

Henec, in order to form a neutral molecules, one Na⁺ combines with one F⁻ to form NaF.

Less stable  hope this