Here's how to determine the number of atoms in 2KClO3:

1. Understand the Chemical Formula:

* KClO3: This represents one molecule of potassium chlorate. It contains:

* 1 potassium atom (K)

* 1 chlorine atom (Cl)

* 3 oxygen atoms (O)

2. Multiply by the Coefficient:

* 2KClO3: The coefficient "2" means we have two molecules of potassium chlorate.

3. Calculate Total Atoms:

* Potassium (K): 2 molecules * 1 K atom/molecule = 2 K atoms

* Chlorine (Cl): 2 molecules * 1 Cl atom/molecule = 2 Cl atoms

* Oxygen (O): 2 molecules * 3 O atoms/molecule = 6 O atoms

4. Total Atoms:

* In 2KClO3, there are a total of 2 + 2 + 6 = 10 atoms.