Question

how many total atoms are in the formula al₂(co₃)₃?
a. 8
b. 9
c. 12
d. 14
e. 18

Explanation:

Step1: Count Al atoms

In \( \text{Al}_2(\text{CO}_3)_3 \), the subscript of Al is 2, so there are 2 Al atoms.

Step2: Count C atoms

Inside the parentheses, \( \text{CO}_3 \) has a subscript of 3 outside. The subscript of C in \( \text{CO}_3 \) is 1, so total C atoms: \( 1\times3 = 3 \).

Step3: Count O atoms

In \( \text{CO}_3 \), subscript of O is 3, and with the outside subscript 3, total O atoms: \( 3\times3 = 9 \).

Step4: Sum all atoms

Total atoms = Al + C + O = \( 2 + 3 + 9 = 14 \).

Answer:

d. 14