Unit 2Atomic Theory

An atom is…The smallest particle into which an element can be divided. “Building block of matter”

Subatomic is…The particles contained in the atom; electrons, protons and neutrons.

A proton is…Positively charged particles in the nucleus of an atom.

A neutron is…Subatomic particle with no charge in the nucleus of an atom.

An electron is…Negatively charged particles found in the outer shells of an atom.

A Nucleus is…The center of the atom, made up of proton and neutrons.

Electron Cloud is…Region surrounding the

nucleus of the atom were the electrons are found.

Elements are…Substances that are the building blocks for all matter.

Valence Electrons are…

Electrons in the outermost energy level; determine an elements chemical properties.

Atomic number isThe number of protons in the nucleus of an atom. Located at top of element block

Atomic Mass is…The average mass of one element. P+N=AM; Located at bottom of element block.