Is there any chemical names listed ?
The best question that could prompt a scientific investigation is: <u>What substances dissolve in ocean water?</u>
This way the person experimenting can use several variables and make observations. Upon making observations, the person can be able to gather as much data as he can in order to answer the original question that he asked.
Iron is a magnetic metal, and it is essential to the Earth's magnetic field!
Essentially it "records" (stores the information, maintains) the direction and orientation of the magnetic field.
Among others, the magnetic field protects the Earth from dangerous cosmic rays.