1, the ocean is the largest water body on the earth, containing a lot of salt and minerals. Among these substances, oxygen is the most abundant element. This is because the water molecules in seawater are composed of two hydrogen atoms and one oxygen atom, so the oxygen content in seawater is very high.
Besides oxygen, seawater contains many other elements, such as sodium, magnesium, calcium and potassium. These elements exist in the form of ions in seawater, which have an important impact on marine ecosystem and human life.
3. For example, sodium ions and chloride ions contained in seawater play an important role in maintaining the survival and reproduction of marine life. At the same time, magnesium ions and calcium ions contained in seawater are also essential minerals for human life and are very important for the health of bones and teeth.
Related knowledge of seawater
1. Composition of seawater: Seawater is mainly composed of water molecules and various salts dissolved in water. Among them, the main salts are sodium chloride, magnesium chloride and calcium chloride. The salinity of seawater is an index to measure the salt content of seawater, usually expressed in parts per thousand. The salinity of seawater in different sea areas is different, which is mainly influenced by climate, topography and rivers.
2. Physical properties of seawater: density: The density of seawater is greater than that of fresh water, and it increases with the increase of salinity. Temperature: The temperature of seawater changes with the change of depth and latitude. Generally speaking, the deep seawater temperature is low and the surface seawater temperature is high. Color: The seawater appears blue or green, mainly because it contains dissolved phytoplankton and zooplankton.
3. Chemical properties of seawater: redox reactions: There are many redox reactions in seawater, such as the change of redox potential, which have an important impact on the material circulation and energy flow of marine ecosystems. Acid-base reaction: Seawater contains a lot of carbonate and bicarbonate, so seawater has a certain acid-base buffering capacity.
4. Ion exchange: Ions in seawater, such as sodium ions and chloride ions, can react with other substances under certain conditions. Utilization of seawater: Exploitation of marine resources: There are abundant seawater resources, such as marine minerals and marine biological resources, which can bring great economic benefits to mankind through development and utilization.