🧬ap biology review

H2O (Water)

Written by the Fiveable Content Team • Last updated August 2025
Verified for the 2026 exam
Verified for the 2026 examWritten by the Fiveable Content Team • Last updated August 2025

Definition

H2O, or water, is a molecule composed of two hydrogen atoms bonded to one oxygen atom. It's essential for all known forms of life and plays a critical role in various biological processes.

"H2O (Water)" also found in:

2,589 studying →