4-2 Flashcards
1
Q
Proton
A
A subatomic particle that has a positive charge and that is found in the nucleus of an atom.
2
Q
Atomic Mass Unit
A
A unit of mass that describes the mass of an atom or molecule
3
Q
Neutron
A
A subatomic particle that has no charge and that is found in the nucleus of an atom
4
Q
Atomic Number
A
The number of protons in the nucleus of an atom; the atomic number is the same for all atoms of an element.
5
Q
Isotope
A
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)
6
Q
Mass number
A
The sum of the numbers of protons and neutrons in the nucleus of an atom
7
Q
Atomic Mass
A
The mass of an atom expressed in atomic mass units
