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.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

b. Protons and neutrons have a positive charge and electrons have a negative charge.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

c. Valence electrons are the electrons in the outermost shell of an atom.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

d. Every element has a characteristic number of protons, which is called the element's mass number.

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.