The atomic mass of water (H2O) can be calculated by summing the atomic masses of its constituent atoms, hydrogen (H) and oxygen (O).
Given: Atomic mass of H = 1.008 amu (approximately) Atomic mass of O = 16.00 amu (approximately)
To calculate the atomic mass of water (H2O): Atomic mass of H2O = 2 × (Atomic mass of H) + (Atomic mass of O) = 2 × 1.008 amu + 16.00 amu = 2.016 amu + 16.00 amu = 18.016 amu
Therefore, the atomic mass of water (H2O) is approximately 18.016 atomic mass units (amu).