a negatively charged subatomic particle

• electron
• proton
• neutron

a positively charged subatomic particle found in the nucleus of an atom

• electron
• proton
• neutron

a stream of electrons produced at the negative electrode (cathode) of a tube containing a gas at low pressure

• cathode ray
• isotope
• AMU

a subatomic particle with no charge, found in the nucleus of an atom

• electron
• proton
• neutron

a unit of mass equal to one twelfth the mass of a carbon-12 atom

• Atomic mass
• Mass number
• Atomic mass unit

atoms of the same element that have the same atomic number but different atomic masses due to a different number of neutrons

• Electron
• Isotope
• Proton

the first theory to relate chemical changes to events at the atomic level

• Dalton’s Atomic
• Mass number
• Atomic Mass

the number of protons in the nucleus of an atom of an element

• atomic mass unit
• atomic mass
• atomic number

the smallest particle of an element that retains its identity in a chemical reaction

• electron
• nucleus
• atom

the tiny, dense central portion of an atom, composed of protons and neutrons

• electron
• nucleus
• atom