1-3 / lesson 6 Electron theory

The flow of the electrons is always from the pole of an electrical energy source that has a deficiency of electrons to the pole that has an excess of electrons. Select one: True False

false

The outer shell (orbit) of an atom is known as the free electron shell. Select one: True False

false

Copper has ? valence electron(s). a. 1 b. 2 c. 3 d. 8

a. 1

The first shell of an atom may contain only ? electrons, while the third shell may hold as many as eighteen. a. 2 b. 4 c. 5 d. 8

a. 2

A(n) ? is generally made from a material that contains one or two valence electrons. a. conductor b. insulator c. semiconductor d. reactor

a. conductor

When a(n) ? is heated, its resistance increases. a. conductor b. insulator c. neutron d. semiconductor

a. conductor

One characteristic of semiconductors is that as they are heated, their resistance ? . a. decreases b. expands c. increases d. stays constant

a. decreases

An atom is composed of a central nucleus surrounded by revolving ? . a. electrons b. neutrons c. protons d. valence ions

a. electrons

Electrical current is the flow of ? . a. electrons b. ions c. neutrons d. protons

a. electrons

A material that allows the electrons to flow easily through it is called a(n) ? . a. compound b. conductor c. inductor d. molecule

b. conductor

Only ? in the valence shell are available to participate in electrical current flow. a. atoms b. electrons c. ions d. protons

b. electrons

With the exception of ? , electrical energy can produce the same effects as those used to produce it. a. chemical action b. friction c. heat d. light

b. friction

The atomic number for copper is ? . a. 13 b. 26 c. 29 d. 32

c. 29

A semiconductor has ? electrons in the valence shell. a. 1 b. 2 c. 4 d. 7

c. 4

The valence shell of any atom can hold no more than ? electrons. a. 2 b. 6 c. 8 d. 18

c. 8

Which material is the best insulator? a. Aluminum b. Carbon c. Rubber d. Silicon

c. Rubber

Materials that do not provide an easy path for the flow of electrons are called ? . a. electrolytic b. electroplating c. insulators d. semiconductors

c. insulators

Electrons revolve around the nucleus in paths called ? . a. arcs b. ellipses c. orbits d. tracks

c. orbits

The direction of current flow is defined as the ? of the circuit. a. current field b. electron flow c. polarity d. potential difference

c. polarity

The best natural conductor of electricity is ? . a. aluminum b. iron c. silver d. steel

c. silver

The maximum number of electrons that can be contained in any orbit is ? . a. 1 b. 6 c. 24 d. 32

d. 32

Which material is the best semiconductor? a. glass b. gold c. plastic d. silicon

d. silicon

The atomic particles in the outermost orbit of the atom are called ? electrons. a. charged b. distant c. loose d. valence

d. valence

Electrons in the inner orbits are even more difficult to move than those in the ? , and are of little interest in the study of electricity. a. core b. orbital ring c. standard shell orbit d. valence ring (shell)

d. valence ring (shell)

Protons have a negative charge and electrons have a positive charge. Select one: True False

false

Semiconductors are good conductors as well as good insulators. Select one: True False

false

Each atom will have the same number of protons and electrons. Select one: True False

true

Electrical current (electron) flow is caused by a potential difference between two poles. Select one: True False

true

Electrical current is produced when an electron from one atom knocks electrons from another atom out of orbit. Select one: True False

true

If too much current flows through a conductor, overheating can occur. Select one: True False

true

Insulators contain seven or eight valance electrons. Select one: True False

true

It requires more energy to remove electrons from those atoms with their outer orbit over half-filled to capacity. Select one: True False

true

Magnesium is considered a metal because it has two valence electrons. Select one: True False

true

Materials with a partially filled valence ring are considered to be chemically unstable. Select one: True False

true

Semiconductors are used in the construction of solid state devices. Select one: True False

true