Chapters 4 and 5

Question 1

The smallest particle of an element that retains its identity in a chemical reaction

Answer 1

Atom

Question 2

The first theory to relate chemical changes to events at the atomic level

Answer 2

Dalton’s atomic theory

Question 3

A negatively charged subatomic particle

Answer 3

Electron

Question 4

A stream of electrons produced at the negative electrode (cathode) of a tube containing a gas at low pressure

Answer 4

Cathode ray

Question 5

A positively charged subatomic particle found in the nucleus of an atom

Answer 5

Proton

Question 6

A subatomic particle with no charge and a mass of 1 amu; found in the nucleus of an atom

Answer 6

Neutron

Question 7

The tiny, dense central portion of an atom, composed of protons and neutrons

Answer 7

Nucleus

Question 8

The number of protons in the nucleus of an atom of an element

Answer 8

Atomic number

Question 9

The total number of protons and neutrons in the nucleus of an atom

Answer 9

Mass number

Question 10

Atoms of the same element that have the same atomic number but different atomic masses due to a different number of neutrons

Answer 10

Isotopes

Question 11

A unit of mass equal to one-twelfth the mass of a carbon-12 atom

Answer 11

Atomic mass unit

Question 12

The weighted average of the masses of the isotopes of an element

Answer 12

Atomic mass

Question 13

The specific energies an electron in an atom or other system can have

Answer 13

Energy level

Question 14

The amount of energy needed to move an electron from one energy level to another

Answer 14

Quantum

Question 15

The modern description, primarily mathematical, of the behavior of electrons in atoms

Answer 15

Quantum mechanical model

Question 16

A mathematical expression describing the probability of finding an electron at various locations; usually represented by the region of space around the nucleus where there is a high probability of finding an electron

Answer 16

Atomic orbital

Question 17

The arrangement of electrons of an atom in its ground state into various orbitals around the nuclei of atoms

Answer 17

Electron configuration

Question 18

The rule that electrons occupy the orbitals of lowest energy first

Answer 18

Aufbau Principle

Question 19

An atomic orbital may describe at most two electrons, each with opposite spin direction

Answer 19

Pauli exclusion Principle

Question 20

A quantum mechanical property of electrons that may be thought of as clockwise or counterclockwise

Answer 20

Spin

Question 21

Electrons occupy orbitals of the same energy in a way that makes the number or electrons with the same spin direction as large as possible

Answer 21

Hund’s rule