Vocab Chem

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 how to find it

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)