chapter 4

Question 1

atom

Answer 1

the smallest unit of an element that maintains the properties of that element

Question 2

electorn

Answer 2

a subatomic particle that has a negative charge

Question 3

nucleus

Answer 3

in physical science an atom’s central region, which is made up of protons and neutrons

Question 4

electron cloud

Answer 4

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

Question 5

proton

Answer 5

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

Question 6

atomic mass unit

Answer 6

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

Question 7

neutron

Answer 7

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

Question 8

atomic number

Answer 8

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

Question 9

isotope

Answer 9

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

Question 10

mass number

Answer 10

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

Question 11

atomic mass

Answer 11

the mass of an atom expressed in atomic mass units