To determine the total number of atoms present in the reaction, we can count the atoms of carbon and oxygen separately.
- Reactants:
- Carbon (C): 10 atoms
- Oxygen (O): 20 atoms
Total atoms in reactants = 10 (C) + 20 (O) = 30 atoms
- Products:
When carbon reacts with oxygen to form carbon dioxide (CO₂), each molecule of CO₂ contains:
- 1 atom of carbon
- 2 atoms of oxygen
For 10 molecules of carbon dioxide (CO₂):
- Carbon atoms = 10 (1 atom of C per molecule × 10 molecules)
- Oxygen atoms = 20 (2 atoms of O per molecule × 10 molecules)
Total atoms in products = 10 (C) + 20 (O) = 30 atoms
According to the law of conservation of matter, the total number of atoms must be the same before and after the reaction.
Therefore, the total number of atoms present in this reaction is 30.