Seawater contains various dissolved elements, primarily derived from the weathering of continental rocks and underwater volcanic activity. The major constituents of seawater are:

- Sodium (Na)

- Chlorine (Cl)

- Magnesium (Mg)

- Sulfur (S)

- Calcium (Ca)

- Potassium (K)

- Carbon (C) (mainly as bicarbonate, carbonate, and dissolved organic matter)

- Bromine (Br)

- Silicon (Si)

- Nitrogen (N) (mostly as nitrate, nitrite, and dissolved organic matter)

-Phosphorus (P) (mostly as phosphate)

- Iodine (I)

- Zinc (Zn)

- Rubidium (Rb)

- Selenium (Se)

- Arsenic (As)

- Copper (Cu)

- Strontium (Sr)

- Molybdenum (Mo)

- Iron (Fe)

Note that while these elements are commonly found in seawater, their concentrations can vary depending on specific geographic locations and the influx of freshwater sources like rivers and glaciers. Some trace elements may be present in even smaller quantities and may vary substantially due to factors such as ocean currents, marine organisms, and human activities.