7th Ch4 Sec. 1-2

Question 1

Atom

Answer 1

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

Question 2

electron

Answer 2

the subatomic particle that has negative charge

Question 3

nucleus

Answer 3

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

Question 4

electron cloud

Answer 4

the 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 charge and that is found in the nucleus of an atom

Question 8

atomic number

Answer 8

the number of protons in the nucleus of an atom; the atomic number is the same for all atoms or 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 numbers 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