After doing some research........(from http://oceanplasma.org/documents/chemistry.html)(works cited so im not plagiarizing)
99% of the total elements occur naturally. They are sodium<span> ion, chloride</span><span>,sulfate, </span>magnesium<span> ion , </span>calcium<span> ion , and </span>potassium<span> ion. other wise Every naturally-occurring element has been found in seawater. here is a link for a picture that might help: https://www.google.com/search?q=chemistry+of+seawater&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiZ756ZivX....:
Answer: The second major source of elements in seawater is the interior of the earth.The elements such as calcium, phosphorous and other minerals are found deep inside the earth's interior.
The interior of earth is full of elements which comes out of the earth by the volcanoes and earthquakes.
These two phenomenon brings the nutrients into the seawater.
Atoms of different elements have different masses because different atoms have a different number of subatomic particles i.e neutrons, protons and electrons.
