The rule    that    electrons   will    occupy  all degenerate  orbitals    in  a   subshell    with    single  electrons   having
parallel    spins   before  entering    half-filled orbitals.
Hybridization
The combination of two or more atomic orbitals to form new orbitals for bonding purposes.
Hydrate
A compound with associated water molecules.
Hydrocarbons
Organic compounds containing only carbon and hydrogen.
Hydrogen bonding
The strong  attraction  between a   hydrogen    atom    bonded  to  a   highly  electronegative atom,   such    as
fluorine    or  oxygen, in  one molecule,   and a   highly  electronegative atom    in  another molecule.
Hydrolysis
A reaction between water and a species in solution.
Hydronium ion
The H 3 O+ ion in aqueous solution.
Hydroxide ion
The OH– ion.
Ideal gas
A   hypothetical    gas whose   behavior    is  described   by  the ideal   gas law under   all conditions. An  ideal
gas would   have    particles   of  zero    volume  that    do  not exhibit interactive forces.