Question

1. the formula for potassium oxide is: ko k₂o k₂o₂ ko₂ 47. how many oxygen atoms are in al₂(so₄)₃? 4 7 12 3

Explanation:

Step1: Determine potassium ion charge

Potassium (K) is in Group 1 of the periodic - table and forms a $K^{+}$ ion with a charge of + 1.

Step2: Determine oxide ion charge

Oxygen (O) is in Group 16 of the periodic - table and forms an $O^{2 - }$ ion with a charge of - 2.

Step3: Balance charges for formula

To balance the charges, we need 2 potassium ions for every 1 oxide ion. So the formula of potassium oxide is $K_{2}O$.

Step4: Count oxygen atoms in $Al_{2}(SO_{4})_{3}$

In the formula $Al_{2}(SO_{4})_{3}$, the sulfate ion ($SO_{4}$) has 4 oxygen atoms. Since there are 3 sulfate ions (the sub - script 3 outside the parentheses), the total number of oxygen atoms is $4\times3 = 12$.

Answer:

1. B. $K_{2}O$
2. C. 12