Final answer:
In the formula CN₂, there are a total of 10 shared electrons.
Step-by-step explanation:
Nitrogen is the central atom in the formula CN₂. The nitrogen atom, with 5 valence electrons, shares 2 electrons with each chlorine atom, which has 7 valence electrons.
There are a total of 10 valence electrons in the CN₂ formula, with 4 from C, 5 from N, and 1 for the -1 charge.