Final answer:
The percent composition of silicon dioxide (SiO2) is approximately 46.9% silicon and 53.1% oxygen.
Step-by-step explanation:
The percent composition of silicon dioxide (SiO2) can be calculated by determining the molar mass of the compound and then calculating the mass of silicon and oxygen in one mole of SiO2.
Molar mass of SiO2 = (1 × atomic mass of Si) + (2 × atomic mass of O) = (1 × 28.1 g/mol) + (2 × 16.0 g/mol) = 60.1 g/mol.
Percent composition of silicon = (mass of silicon / molar mass of SiO2) × 100% = (28.1 g / 60.1 g/mol) × 100% ≈ 46.9%.
Percent composition of oxygen = (mass of oxygen / molar mass of SiO2) × 100% = (2 × 16.0 g / 60.1 g/mol) × 100% ≈ 53.1%.