Which of the following is true of the chemical composition of seawater?
A) Eighteen elements account for 75% of the dissolved waters in seawater.
B) Seawater contains dissolved gases, suspended and dissolved organic matter, and many trace elements.
C) Seawater is very heterogeneous, varying across the vast oceans of the world.
D) Samples of ancient seawater suggest a great deal of chemical variation over the Earth's history.

Question

Quizplus · Accepted Answer

Seawater contains not only salts and minerals but also dissolved gases, suspended and dissolved organic matter, and many trace elements. Option A is incorrect as only six elements - chlorine, sodium, magnesium, sulfur, calcium, and potassium - account for 99% of the dissolved salts in seawater. Option C is incorrect as the chemical composition of seawater is quite uniform throughout the oceans. Option D is also incorrect as samples of ancient seawater indicate a relatively constant chemical composition over time.

Which of the Following Is True of the Chemical Composition