4. How many molecules are in the following formula?
3Fe2O3

Answer:
Option C, 3 molecule is correct
Explanation:
The formula is of Ferric oxide
3Fe2O3
The number 3 ahead the chemical formula represents the number of molecules of the given substance. In general the formula of iron (III) oxide is Fe2O3
Since there are three molecules of it hence the formula is written as 3Fe2O3
Option C, 3 molecule is correct