* C3H8 (Propane): This represents a molecule of propane. It contains:
* Carbon (C): 3 atoms
* Hydrogen (H): 8 atoms
* 5O2 (Oxygen): This represents 5 molecules of oxygen. Each oxygen molecule (O2) contains:
* Oxygen (O): 2 atoms
* Since there are 5 molecules, you have a total of 5 * 2 = 10 oxygen atoms.
Therefore, the total number of elements in the chemical formula C3H8 + 5O2 is 3 (carbon), 8 (hydrogen), and 10 (oxygen) for a total of 21 elements.
Note: It's important to distinguish between elements and atoms. There are only three *different* elements (C, H, and O), but a total of 21 atoms present in the formula.
