Vocab Chem

Atomic Structure, Periodic Table, & Nomenclature Vocabulary

Protons - Positively charged (+), found in the nucleus

Neutrons - Neutrally/no charge, found in the nucleus

Electrons - Negatively charged (-), moves around the nucleus

Isotope - Atoms with the same element but different # of neutrons

Mass Number - Sum of protons + neutrons 

Atomic Mass  - Average mass of an element’s atom

Atomic Number - # of protons in an atom, identifies the element

Metals - Shiny, conductive, malleable, lose electrons easily

Nonmetals - Dull, brittle, non-conductive, gain electrons easily

Metalloids - Elements with both nonmetal and metal properties

Octet Rule - Atoms gain, lose, or share electrons to get 8 in their outer shell

Ion - Atom or molecule with a positive or negative charge

Charge - Positive or negative charge of an ion based on electrons lost/gained

Neutral Atom - Atom with equal protons and electrons, so no charge

Ionic Compounds - Metal + Nonmetal; formed by transferring electrons

Molecular Compounds - Nonmetal + Nonmetal; formed by sharing electrons.

Molecular Formulas - Exact number of atoms (H₂O₂)

Empirical Formulas - Simplified ratio (HO)

Cation - Positively charged ion (lost electrons)

Anion - A negatively charged ion (gained electrons)

Monatomic Ion - A single atom with a single charge

Polyatomic Ion - Group of atoms with a charge (e.g., NO₃⁻, SO₄²⁻)

Diatomic Molecule - A molecule made of two atoms (e.g., O₂, N₂)

Polyatomic Molecule - A molecule made of three or more atoms (e.g., H₂O, CO₂)

Binary Compound - A compound with two different elements (e.g., NaCl, CO)

Ternary Compound - A compound with three different elements (e.g., NaNO₃, H₂SO₄)