Chemical Bond
the attractive force that holds atoms or ions together
Valence Electrons
Electrons in the outermost energy level of an atom that are typically involved in chemical reactions by being gained, lost, or shared in the formation of chemical bonds.
Intramolecular force
forces that hold atoms and ions together in molecules and compounds
Intermolecular force
a weak force of attraction between molecules, includes hydrogen bonds and van der Waals forces
Ionic Bond
Formed when one or more electrons are transferred from one atom to another
Cation
A positively charged ion, usually a metal atom
Anion
A negatively charged ion, usually a nonmetal
Covalent Bonds
Bonds created by sharing electrons with other atoms
Single covalent bond
a bond formed when two atoms share a pair of electrons
Double covalent bond
a bond in which two atoms share two pairs of electrons
Triple covalent bond
a bond in which two atoms share three pairs of electrons
Metallic Bond
a bond formed by the valence electrons moving freely through the metallic substance, often described as a 'sea of mobile electrons'.
Hydrogen bond
Attraction between a slightly positive hydrogen atom and a slightly negative atom, the strongest intermolecular force
Dipole
a molecule that has two poles, or regions, with opposite charges
dipole-dipole forces
attractions between oppositely charged regions of polar molecules
van der Waals forces
a slight attraction that develops between the temporary dipoles in nearby molecules, the weakest intermolecular force
Polyatomic ion
A charged group of covalently bonded atoms (see table E)
Electronegativity
A measure of the ability of an atom in a chemical compound to attract electrons
electronegativity difference
The difference in electronegativities between the atoms in a bond, a measure of bond polarity
Nonpolar covalent bond
a covalent bond in which the electrons are shared equally by the two atoms
Polar covalent bond
A covalent bond in which electrons are not shared equally between atoms
bond polarity
a measure of how equally or unequally the electrons in any covalent bond are shared
chemical formula
Symbols that show the elements in a compound and the ratio of atoms
empirical formula
a formula with the lowest whole-number ratio of elements in a compound
structural formula
a formula that shows the arrangement of atoms in the molecule of a compound.
symmetry
having the same shape, size, and position on both sides of a dividing line
covalent network solids
solids in which the units that make up the three-dimensional network are joined by covalent bonds, examples - diamond and graphite
boiling point
The temperature at which a liquid changes to a gas
melting point
the temperature at which a solid changes to a liquid
vapor pressure
a measure of the force exerted by a gas above a liquid
crystal
any solid material in which the component atoms or ions are arranged in a definite geometric pattern
octet rule
states that atoms tend to form compounds in ways that give them eight valence electrons and thus the electron configuration of a noble gas.
electron dot diagram
A way of representing atoms or molecules by showing electrons as dots surrounding the element symbol
transition metals
various metallic elements in groups 3-12 (such as chromium, iron, and nickel) that have valence electrons in two shells instead of only one, often have more than one oxidation state
electrostatic force
the attraction between opposite charges
oxidation state
the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic.