ADD THEM all, and then divide by four. Thats what I would do!
It shows the atomic number
The answer to this question would be:
NCl3 is a molecular compound (two or more nonmetals), and therefore in its name prefixes indicate the number of each type of atom. so NCl3 is nitrogen trichloride<span>.
</span><span>The compound AlCl3 is an ionic compound (metal and nonmetal), and therefore does not require prefixes. so AlCl3 is aluminum chloride.
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Both of nitrogen and chlorine is nonmetal, but aluminum is metal. Metal with nonmetal will make an ionic compound that doesn't need prefixes.</span>
