2 2.5.2 Test (CST): Computer Scored Unit Test Question 5 of 25
After hydrogen and oxygen, which element makes up almost all of the most
common substances in your body?
O A. Phosphorus
B. Carbon
C. Nitrogen
O D. Calcium

the atomic number of magnesium is 12. its nucleus must contain 12 protons and no electrons. the atomic number of an atom is determined by the number of protons.

magnesium is an electrolyte injection commonly used to treat low magnesium levels in your blood. it is also used to prevent or control seizures in women with preeclampsia or eclampsia.