Chapter 4 Section 2

Question 1

proton

Answer 1

a subatomic practical that has a positive charge and that is found in the nucleus of an atom.

Question 2

atomic mass unit

Answer 2

a unit of mass that describes the mass of an atom or molecule.

Question 3

neutron

Answer 3

a subatomic particle that has no charge and that is found in the nucleus of an atom.

Question 4

atomic number

Answer 4

the number of protons in the nucleus of an atom; the atomic number is the same for all atoms of an element.

Question 5

isotope

Answer 5

an atom that has the same number of protons (or same atomic number) as other atoms of the same element do but that has a different number of neutrons.

Question 6

mass number

Answer 6

the sum of the numbers of protons and neutrons in the nucleus of an atom.

Question 7

atomic mass

Answer 7

the mass of an atom expressed in atomic muss units.

Question 8

periodic

Answer 8

describes something that occurs or repeats at regular intervals.

Question 9

periodic law

Answer 9

the law that states that the repeating chemical and physical properties of elements change periodically with the atomic numbers of the elements.

Question 10

period

Answer 10

in chemistry, a horizontal row of elements in the periodic table.

Question 11

group

Answer 11

a vertical column of elements in the periodic table.