Unit 4 - Chemical Bonding Unit Test Study Guide

electron-dot notation

an electron-configuration notation in which only the valence electrons of an atom of a particular element are shown, indicated by dots placed around the element's symbol

nonpolar-covalent bond

a covalent bond in which the bonding electrons are shared equally by the bonded atoms, resulting in a balanced distribution of electrical charge

polar covalent bond

A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive.

chemical formula

A combination of chemical symbols and numbers to represent a substance

double bond

A covalent bond in which two pairs of electrons are shared between two atoms

molecule

A group of atoms held together by covalent bonds.

octet rule

States that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons

formula unit

The lowest whole-number ratio of ions in an ionic compound

dipole

a molecule that has two poles

hydrogen bonding

A hydrogen bond is the attractive interaction of a hydrogen atom with an electronegative atom, such as nitrogen, oxygen or fluorine

intermolecular forces

forces of attraction between molecules

chemical bond

An attractive force that holds together the atoms, ions, or groups of atoms in a molecule or compound.

covalent bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

ionic bonding

Chemical bonding that results from the electrical attraction between cations and anions

polarity

Any separation of charge into distinct positive and negative regions.

diatomic molecule

A molecule that consists of two atoms of the same element

lewis structures

a dot diagram that provides visual representations of covalent bonding between atoms of a molecule.

lone pair

Pair of electrons associated with one atom in a molecule and not involved in bonding.

molecular compound

A compound consisting of molecules of covalently bonded atoms.

molecular formula

A chemical formula that shows the number and kinds of atoms in a molecule, but not the arrangement of the atoms.

multiple bond

a bond in which the atoms share more than one pair of electrons, such as a double bond or a triple bond

single bond

A pair of shared electrons

structural formula

an expanded molecular formula showing the arrangement of atoms within the molecule

triple bond

A chemical bond formed when atoms share three pairs of electrons

ionic compound

A compound that consists of positive and negative ions

polyatomic ion

An ion made of two or more atoms

ductility

the ability of a substance to be drawn, pulled, or extruded through a small opening to produce a wire

malleability

the ability of a substance to be hammered or beaten into thin sheets

dipole forces

attractions between oppositely charged regions of polar molecules

London dispersion forces

Occur between two instantaneous dipoles; the weakest dipole-dipole force (vs. hydrogen bonds which are the strongest dipole-dipole forces).

molecular polarity

is dependant on the difference in electronegativity between atoms in a complound and the asymmetry of the compound's structure