To determine how many oxygen atoms are present in one formula unit of potassium carbonate ([tex]\(K_2CO_3\)[/tex]), let's analyze its chemical formula step-by-step.
1. Identify the elements and their quantities in the formula:
- Potassium (K): There are 2 potassium atoms.
- Carbon (C): There is 1 carbon atom.
- Oxygen (O): There are 3 oxygen atoms.
2. Focus on the oxygen atoms:
- The formula [tex]\((K_2CO_3)\)[/tex] clearly shows that there are 3 oxygen atoms associated with it.
3. Conclude the number of oxygen atoms:
- From the chemical notation, it's evident that the potassium carbonate molecule contains exactly 3 oxygen atoms.
So, the number of oxygen atoms present in one formula unit of potassium carbonate ([tex]\(K_2CO_3\)[/tex]) is:
[tex]\[ \boxed{3} \][/tex]
Hence, among the given options:
- 1.5 atoms
- 2 atoms
- 1 atom
- 3 atoms
The correct answer is 3 atoms.