Atom
Smallest particle of an element
Atomic Number
the number of protons in the nucleus of an atom
Nucleus
center of an atom made of protons and neutrons
Atomic Mass
the number of protons and neutrons in an atom
Isotope
An atom with the same number of protons and a different number of neutrons from other atoms of the same element.
Ion
An atom or group of atoms that has a positive or negative charge.
Electron
a negatively charged subatomic particle
Proton
A subatomic particle that has a positive charge and that is found in the nucleus of an atom
Neutron
A subatomic particle that has no charge and that is found in the nucleus of an atom
Energy Level/ Electron Cloud
the region surrounding an atom's nucleus where one or more electrons are most likely to be found
Mass Number
the total number of protons and neutrons in the nucleus of an atom
Electron Dot Diagram
a model that represents valence electrons in an atom as dots around the element's chemical symbol
Valence Electron
an electron that is found in the outermost shell of an atom and that determines the atom's chemical properties
Metalloids
elements with properties that fall between those of metals and nonmetals
Metals
Elements that are good conductors of electric current and heat.
Nonmetals
Elements that are poor conductors of heat and electric current
The Periodic Table is organized by
atomic number (number of protons)