Chapter 12 Chemical Bonds and Mixtures 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.

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. 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.

Mole

A large number equal to 6.02214076×10²³; 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.

Precipate

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.

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.