Chapter 5

Question 1

electron

Answer 1

a subatomic particle that has a negative charge

Question 2

nucleus

Answer 2

in physical science, an atoms central region, which is made up of protons and neutrons

Question 3

electron cloud

Answer 3

a region around the necleus of an atom where electrons are likely to be found

Question 4

proton

Answer 4

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

Question 5

atomic mass unit

Answer 5

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

Question 6

neutron

Answer 6

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

Question 7

atomic number

Answer 7

the number of protons in the nucleus of an atom, the atomic number is the same for all atoms of an elements

Question 8

isotope

Answer 8

an atom has the same number of protons or atomic number as other atoms of the same elements do but that has a different number of neutron and thus different atomic number

Question 9

mass number

Answer 9

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

Question 10

atomic mass

Answer 10

the mass of an atom expressed in atomic mass units