Chapter 4

Question 1

Nucleus

Answer 1

The nucleus of an atom is made of protons and neutrons. The nucleus itself has a positive charge.

Question 2

Proton

Answer 2

Protons have a positive electric charge.

Question 3

Neutrons

Answer 3

Neutrons have no charge.

Question 4

Electrons

Answer 4

Electrons have a negative electric charge.

Question 5

Orbital

Answer 5

An orbital is a region in an atom where there is a high probability of finding electrons.

Question 6

Valence electrons

Answer 6

Valence electrons are found in the outermost shell of an atom and determine the atom’s chemical properties.

Question 7

Periodic law

Answer 7

The periodic law states that when elements are arranged this way, similarities in their properties will occur in a regular pattern.

Question 8

Period

Answer 8

A period is a horizontal row in the periodic table.

Question 9

Group

Answer 9

A group is a vertical column of elements in the periodic table.

Question 10

Ion

Answer 10

An ion is an atom or group of atoms that has lost or gained one electrons and has a negative or positive charge.

Question 11

Atomic number

Answer 11

The atomic number of an atom equals the number of protons in the nucleus.

Question 12

Mass number

Answer 12

The mass number of an atom equals the number of protons plus the number of neutrons in the nucleus.

Question 13

Isotope

Answer 13

An isotope is an atom that has the same number of protons as other atoms of the same element do,but that has a different number of neutrons.

Question 14

Atomic mass unit

Answer 14

An atomic mass unit is equal to one twelfth of the mass of an atom.

Question 15

Average atomic mass

Answer 15

The average atomic mass for an element is a weighted average of the masses of all naturally-occurring isotopes of an element.

Question 16

Metal

Answer 16

Metals are shiny and conduct heat and electricity well.

Question 17

Nonmetal

Answer 17

A nonmetal is an element that are found on the right side of the periodic table, and may be solids, liquids, or gases at room temperature.

Question 18

Semiconductor

Answer 18

A semiconductor is an element that can conduct electricity under certain conditions. They are grouped between metals and nonmetals.

Question 19

Alkali metals

Answer 19

Alkali metals are found in Group 1, and are very reactive.

Question 20

Alkaline earth metals

Answer 20

Alkaline earth metals are found in Group 2, and are less reactive than the alkali metals.

Question 21

Transition metals

Answer 21

Transition metals are are found in Group 3-12 of the periodic table.

Question 22

Halogen

Answer 22

Halogens are located in Group 17 of the periodic table.

Question 23

Noble gases

Answer 23

Nobel gases are different from most elements that are gases, because they exist as single atoms instead of as molecules.

Question 24

Mole

Answer 24

A mole is a collection of a very large number of particles.

Question 25

Avogadro’s constant

Answer 25

Avogadro’s constant is written as 6.022 x 10^23

Question 26

Molar mass

Answer 26

The mass in grams of 1 mole of a substance is called its molar mass.

Question 27

Conversion factors

Answer 27

Conversion factors are when you can convert moles to grams and vice versa, since the amount of a substance and its mass are related.