Vocab

Question 1

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

Answer 1

atom

Question 2

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

Answer 2

Atomic Mass

Question 3

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

Answer 3

Atomic mass unit (AMU)

Question 4

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

Answer 4

Atomic Number

Question 5

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

Answer 5

Cathode Ray

Question 6

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

Answer 6

Dalton’s Atomic Theory

Question 7

A negatively charged subatomic particle

Answer 7

Electron

Question 8

A vertical column of elements in the periodic table; the constituent elements of a group have similar chemical and physical properties.

Answer 8

Group

Question 9

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

Answer 9

Isotopes

Question 10

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

Answer 10

Mass number

Question 11

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

Answer 11

neutron

Question 12

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

Answer 12

nucleus

Question 13

A horizontal row of elements in the periodic table

Answer 13

period

Question 14

An arrangement of elements in which the elements are separated into groups based on a set of repeating properties.

Answer 14

Periodic Table

Question 15

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

Answer 15

Proton