How to Draw the Lewis Structure for Calcium Chloride

To draw the Lewis structure for calcium chloride (CaCl₂), follow these steps:

1. Determine the total number of valence electrons:
   • Calcium (Ca) is in Group 2 of the periodic table, so it has 2 valence electrons.
   • Chlorine (Cl) is in Group 17, so each chlorine atom has 7 valence electrons. Since there are two chlorine atoms, the total number of valence electrons from chlorine is 14.
   • Add the valence electrons from calcium and chlorine: 2 + 14 = 16 valence electrons.
2. Place the least electronegative atom in the center:
   • Calcium is less electronegative than chlorine, so it will be the central atom.
3. Connect the outer atoms to the central atom with single bonds:
   • Draw a single bond (represented by a line) between calcium and each chlorine atom. This uses 4 valence electrons (2 bonds × 2 electrons each).
4. Distribute the remaining valence electrons:
   • After forming the bonds, you have 12 valence electrons left (16 – 4 = 12).
   • Place the remaining electrons around the chlorine atoms to complete their octets. Each chlorine atom needs 6 more electrons to complete its octet (since they already have 2 electrons from the bond).
   • Add 6 electrons (3 lone pairs) to each chlorine atom.
5. Check the octet rule:
   • Calcium has 2 valence electrons, which is its full outer shell (it follows the duet rule).
   • Each chlorine atom has 8 valence electrons, satisfying the octet rule.

The final Lewis structure for calcium chloride (CaCl₂) shows calcium in the center with two single bonds to chlorine atoms, and each chlorine atom has three lone pairs of electrons.