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smallest piece of matter that retains the property of the element

Atomic Number

number of proteins in an atom's nucleus

Average Atomic Mass

weighted-average mass of the mixture of an element's isotopes


negatively charged particles surrounding the center of an atom

Electron Cloud

area around the nucleus of an atom where the atom's electrons are most likely to be found

Electron Dot Diagram

uses the symbol for an element and dots representing the number of electrons in the element's outer energy level


positively charged particle,composed of quarks,inside the nucleus of an atom


positively charged center of an atom that contains protons ans neutrons and is surrounded by a cloud of electrons


atoms of the same element that have different numbers of neutrons

Mass Number

sum of the number of protons and neutrons in an atom's nucleus


neutral particle, composed of quarks,inside the nucleus of an atom

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