BI108 Chemistry of Life

Atom

smallest fundamental unit

Protons

positive charge (in the nucleus)

Electrons

negative charge

Neutrons

neutral charge (no charge; in the nucleus)

Ion

electrically charged particles formed when atoms lose or gain electrons

Ionic bond

bonds formed by the electrical attraction of positive and negative ions

Molecule

a structure made of two or more atoms that are connected to each other by chemical bonds

Covalent bond

an attraction between two atoms based on shared electrons

Double bonds

covalent bonds that involve two pairs of electrons (total of four electrons)

Electronegativity

the tendency for an atom's nucleus to attract the shared electrons in a covalent bond

Polar covalent bond

electrons are shared unequally in a covalent bond

Nonpolar covalent bond

electrons are shared equally

Hydrogen bond

an attraction between a partial positive charge on a hydrogen atom of one molecule and a partial negative charge on an atom in a different molecule (usually oxygen or nitrogen)

van de Waals forces

weak, temporary interactions between neighboring atoms

Hydrophilic

a molecule that can interact with partial charges on water

Hydrophobic

a molecule that constraints mostly nonpolar covalent bonds; cannot interact with the partial charges on water

pH

a measurement of how acidic or basic a solution is

Acid

an ion or molecule that releases a proton

Base

an ion or molecule that acquires a proton