HPS2 CH 12 Terms

Alloy

A mixture of two or more metallic elements.

Concentration

A quantitative measure of the amount of solute in a solution.

Covalent bond

A chemical bond in which atoms are held together by their mutual attraction for two or more shared electrons.

Covalent compound

A substance, such as an element or a chemical compound, in which atoms are held together by covalent bonds.

Dipole

A separation of charge that occurs in a chemical bond because of differences in the electronegativities of the bonded atoms.

Dissolving

The process of mixing a solute in a solvent to produce a homogeneous mixture.

Electron dot structure

A shorthand notation of the noble gas shell model of the atom, in which valence electrons are shown as dots surrounding an atomic symbol. The electron-dot structure for an atom or ion is sometimes called a Lewis dot symbol, and the electron-dot structure for a molecule or polyatomic ion is sometimes called a Lewis structure.

Electronegativity

The ability of an atom to attract a bonding pair of electrons to itself when bonded to another atom.

Heterogeneous mixture

A mixture in which the different components can be seen as individual substances.

Homogeneous mixture

A mixture in which the components are so finely mixed that any one region of the mixture has the same ratio of substances as any other region

the components cannot be seen as identifiable individual substances.

Hydrogen bond

An unusually strong dipole–dipole attraction between molecules that have a hydrogen atom covalently bonded to a highly electronegative atom, usually nitrogen, oxygen, or fluorine.

Induced dipole

A temporarily uneven distribution of electrons in an otherwise nonpolar atom or molecule.

Ion

An atom that has a net electric charge because of either a loss or gain of electrons.

Ionic bond

A chemical bond created by an electrical attraction between two oppositely charged ions.

Ionic compound

A chemical compound containing ions.

Metallic bond

A chemical bond in which positively charged metal ions are held together within a “fluid” of loosely held electrons.

Mixture

A combination of two or more substances in which each substance retains its own properties.

Molarity

A common unit of concentration equal to the number of moles of a solute per liter of solution.

Mole

A large number equal to 6.02 × 10 to the 23rd power; usually used in reference to the number of atoms, ions, or molecules within a macroscopic amount of a material.

usually used in reference to the number of atoms, ions, or molecules within a macroscopic amount of a material.

Molecule

The fundamental unit of a chemical compound, which is a group of atoms held together by covalent bonds.

Nonbonding pairs

Two paired valence electrons that do not participate in a chemical bond.

Nonpolar

Description of a chemical bond or molecule that has no dipole

the electrons are distributed evenly.

Polar

Description of a chemical bond or molecule that has a dipole

the electrons are congregated on one side, which makes that side slightly negative while the opposite side (lacking electrons) becomes slightly positive.

Polyatomic ion

A molecule that carries a net electric charge.

Precipitate

A solute that has come out of solution.

Pure

The state of a material that consists of only a single element or compound.

Saturated solution

A solution containing the maximum amount of solute that will dissolve in its solvent.

Solubility

The ability of a solute to dissolve in a given solvent.

Soluble

Capable of dissolving to an appreciable extent in a given solvent.

Solute

Any component in a solution that is not the solvent.

Solution

A homogeneous mixture in which all components are in the same phase.

Solvent

The component in a solution that is present in the largest amount.

Suspension

A homogeneous mixture in which the various components are thoroughly mixed but remain in different phases.

Unsaturated solution

A solution that is capable of dissolving additional solute.

Valence electron

The electrons in the outermost occupied shell of an atom.

Valence shell

The outermost occupied shell of an atom.