Unit 2 The Atom Vocabulary

Front

Atom

Back

Smallest unit of an element

Front

Proton

Back

Positive subatomic particle in nucleus

Front

Neutron

Back

Neutral subatomic particle in nucleus

Front

Electron

Back

Negative subatomic particle in electron cloud

Front

Valence electrons

Back

Electrons in outermost energy level

Front

Quarks

Back

Make up protons and neutrons

Front

Atomic number

Back

Number of protons in an atom

Front

Mass number

Back

Number of protons and neutrons in nucleus

Front

Groups

Back

Vertical columns on periodic table

Front

Periods

Back

Horizontal rows on periodic table