Chemistry Chap 3

amu

abbreviation for atomic mass unit

atomic mass (element)

average relative mass of the isotopes of an element in amu

nucleus

central part of an atom where protons and neutrons are located

atomic model

model that shows the structure of an atom and the arrangement of subatomic particles in an atom

electron cloud

outer part of an atom where electrons are located

isotopic abundance

percent of an isotope of an element in nature

atomic mass (atom)

relative mass of an atom in amu

atomic mass unit

unit of relative mass equal to 1/12 the mass of a carbon- 12 atom

isotopic notation

notation that shows the chemical symbol, atomic number, and mass number for an isotope of an element

atomic number

number of protons in an atom

subatomic particles

one of three basic particles that make up an atom

neutron

subatomic particle that is electrically neutral

mass number

sum of the number of protons and neutrons in an atom

nucleon

term for a subatomic particles in the nucleus of an atom

Atomic Theory

theory that says that substances are composed of atoms and chemical reactions involve interactions of atoms

atom

smallest particle of an element that can enter into a chemical reaction

electron

subatomic particle that has a negative

proton

subatomic particle that has a positive charge

isotope

variety of atom of an element that has a distinctive number of neutrons