Chapter 9 Vocab

smallest piece of an element that still represents the element

• atom

• electron

• proton

• neutron

atomic particle with one negative charge

• atom

• neutron

• proton

• electron

neutral particle in the nucleus of an atom

• atom

• neutron

• proton

• electron

atomic particle with one positive charge

• atom

• neutron

• proton

• electron

area around an atomic nucleus where an electron is most likely found

• nucleus

• electron cloud

• ion

• isotope

small area in the center of an atom in which most of an atom's mass and positive charge is concentrated

• nucleus

• electron cloud

• ion

• isotope

atom that is no longer neutral because it has gained or lost an electron

• nucleus

• electron cloud

• ion

• isotope

any of two or more atoms of the same element that have different numbers of neutrons

• nucleus

• electron cloud

• ion

• isotope

number of protons in an atom of an element

• mass number

• average atomic mass

• atomic number

average mass of an element's isotopes

• mass number

• average atomic mass

• atomic number