The average oxygen atom has a mass number of 16 and an atomic number of 8. This means that the number of neutrons in this oxygen atom is:
a) 24.
b) 8.
c) 16.
d) 4.
e) 2.

Which of the following can be most accurately described as a decomposition reaction?

a. C₆H₁₂O₆ + 6 O₂ → 6 H₂O + 6 CO₂

b. glucose + ATP → glucose phosphate + ADP

c. 6 H₂O + 6 CO₂ → C₆H₁₂O₆ + 6 O₂

d. A + BC → AB + C

Nitrogen exists primarily as _____ in the environment.

Organisms typically make use of phosphorus in the form of _____.

A proton ___________:

a) Has one positive charge.

b) Has one AMU.

c) Is found in the nucleus of the atom.

d) Only a and b are true.

e) a, b, and c are true.

How many valence electrons does an atom with five total electrons have?

a) 5.

b) 7.

c) 3.

d) 2.

e) 1.

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.

A neon atom (Ne) is unreactive for which of the following reasons?

a) It has 7 valence electrons.

b) It has 8 valence electrons.

c) Its valence shell is full of electrons. 

d) It has 20 valence electrons.

e) b and c only.

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.