Question

count the atoms! ga(clo₄)₃

Explanation:

Step1: Analyze Ga atoms

There is 1 Ga atom as there is no sub - script next to Ga.

Step2: Analyze Cl atoms

The sub - script 3 outside the parentheses multiplies the Cl inside. So, there are 3 Cl atoms ($1\times3$).

Step3: Analyze O atoms

There are 4 O atoms in each $ClO_4$ group and 3 such groups. So, there are 12 O atoms ($4\times3$).

Step4: Calculate total atoms

Add the number of Ga, Cl and O atoms. $1 + 3+12=16$ atoms.

Answer:

16