By the 1960s, they knew the basic ingredients of chemiluminescence: a molecule that produces light when it has been excited (like a fluorescent dye), and a chemical reaction that produces enough energy to excite the light-producing molecule.
(they; knew; the basic ingredients of chemiluminescence) (a molecule; produces; light; T:when it has been excited (like a fluorescent dye) (it; has been excited; ) (a chemical reaction; produces; enough energy to excite the light-producing molecule)
they a molecule it a chemical reaction
knew produces has been excited produces
the basic ingredients of chemiluminescence
light T:when it has been excited (like a fluorescent dye
enough energy to excite the light-producing molecule