Chemical processes in oceans involve various reactions that affect water composition and marine life. One key process is photosynthesis, where phytoplankton use sunlight to convert carbon dioxide and water into oxygen and glucose. This process not only produces oxygen but also forms the base of the ocean food web. Another important process is ocean acidification, which occurs when excess carbon dioxide from the atmosphere dissolves in seawater, forming carbonic acid. This can lower the pH of the ocean, impacting coral reefs and shellfish that rely on calcium carbonate for their structures. Understanding these processes is crucial for marine ecosystem health.