Answer:

isomers

Answer	Crossword Clue
ISOMERS	Chemically similar substances
ISOMERS	Glucose and fructose, e.g.
ISOMERS	Butane and methylpropane

ISOMERS	Chemical compounds
ISOMERS	Related compounds
ISOMERS	Atomic rearrangements
ISOMERS	Chemical analogues
ISOMERS	Chemically related compounds
ISOMERS	Chemical compounds of similar structure.
ISOMERS	Compounds of like makeup.
ISOMERS	Variants of a compound

ISOMERS	Chemical compounds resembling others
ISOMERS	Compounds used by nuclear physicists
ISOMERS	Compounds relating with others
ISOMERS	Ethanol and dimethyl ether, e.g.
ISOMERS	Paired nuclides
ISOMERS	Glucose and galactose, e.g.
ISOMERS	Certain similar chemical compounds
ISOMERS	Atomically related compounds

ISOMERS	Beta carotene and others
ISOMERS	Chemical cousins, in a way
ISOMERS	Chemical cousins
ISOMERS	Compound variants
ISOMERS	Some similar chemical compounds
ISOMERS	Beta carotene and the like
ISOMERS	Similar chemical compounds