3. Chemical Principles of Microbiology

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.

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.

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.

What is a chemical element?

DRAW IT Diagram the electronic configuration of a carbon atom.

The term trace elements refers to

a. the elements CHONPS.

b. vitamins.

c. nitrogen, phosphorus, and sulfur.

d. small mineral requirements.

e. toxic substances.

Using the periodic table, answer the following questions:

a. What is the atomic number for lithium (Li)?

b. What is the atomic mass of oxygen (O)?

c. What is the chemical symbol for potassium?

d. How many protons does nitrogen have?

e. How many neutrons does lead have?

What ions result when hydrogen donates one electron to fluorine?

Label the features of the periodic table box: <IMAGE>

Which of the following structures have no electrical charge?

a. protons

b. electrons

c. neutrons

d. ions

The atomic mass of an atom most closely approximates the sum of the masses of all its __________.

a. protons

b. isotopes

c. electrons

d protons and neutrons

The outermost electron shell of an atom is known as the _____________ shell.