Question

Use Lewis symbols to represent the reaction that occurs between \(\mathrm{Ca}\) and \(\mathrm{F}\) atoms.

Short answer

The reaction between calcium (Ca) and fluorine (F) can be represented using Lewis symbols as follows: \( \overset{\displaystyle .}{\:Ca\:.} + 2F\: {\Large\circ} \rightarrow \:Ca^{2+} + 2F^{-} \) In this reaction, Ca loses its 2 valence electrons and forms Ca^{2+} while each F atom gains one electron and forms F^{-}. The ionic bond forms between one Ca atom and two F atoms.

Step-by-step solution

Find the number of valence electrons for each atom.

To find the number of valence electrons in each atom, we can use the periodic table. Locate the elements, calcium (Ca) and fluorine (F). Calcium is in group 2, which means it has 2 valence electrons, and fluorine is in group 17 (group 7 for non-transition metals), so it has 7 valence electrons.

Draw the Lewis symbol for each atom.

Now that we know the number of valence electrons for each element, we can draw their respective Lewis symbols. Calcium (Ca) has 2 valence electrons, so we'll place 2 dots around the Ca symbol. Ca: \( \overset{\displaystyle .}{\:Ca\:.} \) Fluorine (F) has 7 valence electrons. As per the Lewis symbol convention, we'll place all unpaired electrons clockwise, starting at the top and moving to the sides before placing the lone pairs opposite of each other. \(F\: {\Large\circ} \)

Determine the type of bond that will form.

To predict the type of bond that will form between calcium and fluorine, we can use their positions in the periodic table. Calcium (Ca) is a metal and fluorine (F) is a nonmetal. When metals react with nonmetals, they generally form ionic bonds. If an ionic bond forms, Ca will lose its valence electrons to F, and both elements will attain stable electron configurations.

Show the transfer of electrons using Lewis symbols.

As we've determined that an ionic bond will form between Ca and F, let's represent this by showing the transfer of electrons in the Lewis symbols. Calcium (Ca) will lose its 2 valence electrons, and two fluorine atoms, which are each trying to gain an electron to complete their octet, will pick up one electron each. Ca: \( \overset{\displaystyle .}{\:Ca\:.} \rightarrow \:Ca^{2+} \) \(F\: {\Large\circ} \rightarrow \:F^- \)

Write the final reaction representing the ionic bond between Ca and F.

Now that we've shown the transfer of electrons and formation of ions, we can write the final reaction using the Lewis symbols. Since calcium lost two electrons and each fluorine gained one electron, two F atoms will react with one Ca atom. The final reaction is: \( \overset{\displaystyle .}{\:Ca\:.} + 2F\: {\Large\circ} \rightarrow \:Ca^{2+} + 2F^{-} \) This represents the reaction between calcium (Ca) and fluorine (F) using Lewis symbols.