1. Find the molar mass of each element:

* Carbon (C): 12.01 g/mol

* Hydrogen (H): 1.01 g/mol

* Oxygen (O): 16.00 g/mol

2. Calculate the molar mass of the compound:

* C₂H₄O₂ = (2 * 12.01) + (4 * 1.01) + (2 * 16.00) = 60.06 g/mol

3. Calculate the mass of oxygen in the compound:

* Mass of oxygen = (2 * 16.00 g/mol) = 32.00 g/mol

4. Calculate the percentage of oxygen:

* (Mass of oxygen / Molar mass of the compound) * 100%

* (32.00 g/mol / 60.06 g/mol) * 100% = 53.28%

Therefore, the percentage of oxygen in C₂H₄O₂ is approximately 53.28%.