In a water molecule (H2O), how many hydrogen atoms are present?

In a water molecule, there are two hydrogen atoms bonded to one oxygen atom, giving the molecular formula H2O. This formula indicates that for every molecule of water, two hydrogen atoms are involved in the structure. Water is a polar molecule, which means the oxygen atom has a partial negative charge due to its higher electronegativity, while the hydrogen atoms have a partial positive charge. This bonding arrangement is crucial for the unique properties of water, including its solvent capabilities, high heat capacity, and surface tension. Understanding this composition is fundamental in biology since water plays an essential role in biological systems, including cellular processes and metabolic reactions.