Question

what atoms are present in al₂(so₄)₃? (options: 4, 7, 24, 12)

Explanation:

Step1: Identify atoms in \( \text{Al}_2(\text{SO}_4)_3 \)

• Aluminum (\( \text{Al} \)): subscript 2, so 2 atoms.
• Sulfur (\( \text{S} \)): in \( \text{SO}_4 \), subscript 1, and \( (\text{SO}_4)_3 \), so \( 1\times3 = 3 \) atoms.
• Oxygen (\( \text{O} \)): in \( \text{SO}_4 \), subscript 4, and \( (\text{SO}_4)_3 \), so \( 4\times3 = 12 \) atoms.

Step2: Sum the number of atoms

Total atoms \( = 2 + 3 + 12 = 17 \)? Wait, no, maybe the question is about "different atoms" (elements) present? Wait, the options are 4,7,24,12. Wait, maybe the formula is \( \text{Al}_2(\text{SO}_4)_3 \), the elements are Al, S, O. Wait, no, maybe the question is about the number of oxygen atoms? Wait, \( \text{SO}_4 \) has 4 O, times 3 is 12. Oh! The options include 12. So maybe the question is "How many oxygen atoms are present in \( \text{Al}_2(\text{SO}_4)_3 \)?"
So:

• In \( \text{SO}_4^{2-} \), O atoms: 4.
• There are 3 \( \text{SO}_4^{2-} \) groups, so \( 4\times3 = 12 \).

Answer:

12 (corresponding to the option with 12)