Radioactive elements are useful for the study of the biological system because of the unique properties which they possess. For instance isotopes of radioactive elements can be used to label a specific molecule in order to be able to follow the movement of this molecule as it navigates through the human system.
The answer is D, You can keep the population of the crops balanced so you don't over harvest them.
Answer:
A. Crust
Explanation:
The most common chemical elements in the crust are oxygen (46.6%), silicon (27.7), aluminum (8.1), iron (5.0), calcium (3.6), potassium (2.8), sodium (2.6), and magnesium (2.1). These figures vary among different studies because we really have no way to know for sure.
