Download Terms Used in Part 3

Unit 6 Vocabulary Part 3
Atom: The smallest unit of matter that retains the identity of the
substance.
Proton: subatomic particle with a positive charge and located in
the nucleus of the atom. The number of protons gives the atom its
identity.
Neutron: subatomic particle with no charge, the same mass as a
proton, and located in the nucleus of the atom.
Electron: subatomic particle with a negative charge and located
outside the nucleus.
Atomic number: the number of protons in the nucleus of an atom.
This number identifies the atom.
Atomic mass: the average mass number of all isotopes of an
atom. Round this number to find the mass number of the atom.
Isotope: Atom with the same number of protons but a different
number of neutrons and is of the same element.
Mass number: the number of protons and neutrons in the nucleus
of an atom. Mass number = protons + neutrons
Nucleus: the central part of the atom containing protons and
neutrons.
Electron Cloud: region surrounding the nucleus of an atom where
electrons are most likely to be found.