Final answer:
After balancing the given chemical equation, there are 14 oxygen atoms on the reactant side, provided by 7 molecules of O2.
Step-by-step explanation:
The student has asked about the number of oxygen atoms on the reactant side after balancing the chemical equation:
2 C2H6 + O2 → 4 CO2 + 6 H2O
To balance the equation, it's evident that we have 14 oxygen atoms on the product side (4 CO2 molecules have 8 oxygen atoms, and 6 H2O molecules have 6 oxygen atoms, which adds up to 14). Therefore, to have the same number on the reactant side, we need 7 O2 molecules, because each molecule of O2 contains 2 oxygen atoms (7 x 2 = 14). The balanced equation would have 7 oxygen molecules on the reactant side, giving a total of 14 oxygen atoms.