Question

Create the Lewis structure of CF4. NOTE: do only the step asked for in each part and then click Check–don't work ahead to solve the final structure.
Step 1. Count valence electrons in the molecule or ion. Do this by adding the periodic group numbers for each atom in the structure and adjusting for charge. Enter and Check.

Answer 1

To create the Lewis structure we need to take into account the octet rule: atoms tend to gain, lose or share electrons to complete their valence shell with 8 electrons.

C belongs to Group 4A in the periodic table so it has 4 valence electrons. It needs to share 4 pairs of electrons to complete the octet.

F belongs to Group 7A in the periodic table so it has 7 valence electrons. Each F needs to share 1 pair of electrons to complete the octet.

As a consequence, in CF₄, C will form a single bond with each F and all the octets will be complete.