changes in the individual reactions that comprise it.
Heterogeneous
Heterogeneous
Nonuniform  in  composition.Homogeneous
Homogeneous
Uniform in  composition.Hund’s rule
Hund’s  rule
The rule    that    electrons   will    occupy  all degenerate  orbitals    in  a   subshell    with    single  electrons
having  parallel    spins   before  entering    half-filled orbitals.
Hybridization
Hybridization
The combination of  two or  more    atomic  orbitals    to  form    new orbitals    for bonding purposes.Hydrate
Hydrate
A   compound    with    associated  water   molecules.Hydrocarbons
Hydrocarbons
Organic compounds   containing  only    carbon  and hydrogen.