Question

which compound shows a correctly written formula between the atoms shown?
a. alar
b. alar₃
c. alcl
d. alcl₃

Explanation:

Step1: Identify the elements

The first atom has 13 protons (p), so it is aluminum (Al) with a common +3 oxidation state. The second atom has 17 protons, so it is chlorine (Cl) with a - 1 oxidation state.

Step2: Determine the formula

To form a neutral compound, the charges must balance. Since Al has a +3 charge and Cl has a -1 charge, we need 3 Cl atoms for every 1 Al atom. So the formula is AlCl₃.

Answer:

D. AlCl₃