3. Chemical Principles of Microbiology

The term trace elements refers to

a. The elements CHONPS.

b. Vitamins.

c. Nitrogen, phosphorus, and sulfur.

d. Small mineral requirements.

e. Toxic substances.

Nitrogen exists primarily as _____ in the environment.

What ions result when hydrogen donates one electron to fluorine?

How many electrons does an Oxygen atom need to fulfill the octet rule by filling its valence shell?

a) 8.

b) 4.

c) 1.

d) 2.

e) 6.

Which of the following is true about electron energy shells?

a) They represent regions around the nucleus in which the electrons orbit.

b) The shells closest to the nucleus contain electrons with higher energy.

c) They contain electrons of the same energy.

d) a and b only.

e) a and c only.