Answer:
C
Step-by-step explanation:
Remark
You have to take into account what the brackets mean. They enclose a complex ion. So (SO4)3 means that you multiply the number of atoms inside the brackets by the number on the right.
Sulphur for example has a 1 after it, but the 3 on the outside multiplies the 1 by 3.
Oxygen has 4 after it. So the number of oxygens is 4*3 = 12
Givens
- Blue = Aluminum
- yellow = sulphur
- green = oxygen
Answer
Blue = 2
Yellow = 3
Green = 12
C