Answer:
C - Magnesium Chloride
Explanation:
The metal in a compounds name is always pronounced, and if the last element is a non-metal, the first half of the element is used and the last part is replaced with "ide"
Lithium 6 would have 6 valence electrons in the outer orbital, while lithium 7 would have 7 in the outer orbital.
Magnesium is the correct answer