Front

mass number

Back

sum of the number of protons and neutrons

Front

atomic number

Back

number of protons in an atom

Front

isotope

Back

atoms of the same element with different numbers of neutrons

Front

ion

Back

an atom or molecule with a net electric charge due to the loss or gain of one or more electrons

Front

nuclide

Back

any particle in the nucleus

Front

proton

Back

positive subatomic particle found in the nucleus

Front

neutron

Back

neutral subatomic particle found in the nucleus

Front

electron

Back

negatively charged subatomic particle orbiting the nucleus

Front

atomic mass

Back

average mass of atoms of an element, calculated using the relative abundance of isotopes

Front

nucleus

Back

a location at the center of an atom