<p><strong>Fig. 2.2.</strong>&nbsp; (<strong>A</strong>) Pure water consists of only hydrogen and oxygen combined into water molecules (H<sub>2</sub>O). (<strong>B</strong>) Seawater is a mixture of pure water and dissolved ionic substances.</p>

Fig. 2.2.  (A) Pure water consists of only hydrogen and oxygen combined into water molecules (H2O). (B) Seawater is a mixture of pure water and dissolved ionic substances.

Image by Byron Inouye