chemical composition; chemical component
Refers to the chemical makeup or a specific chemical constituent of a substance. Common in scientific and technical contexts.
We analyzed the chemical composition of this mineral.
The chemical components of the food are listed.
化学組成 is a more formal or technical term for 'chemical composition', often used in geology or materials science, while 化学成分 is broader and can refer to individual components.
Compound of 化学 (かがく, 'chemistry') and 成分 (せいぶん, 'component, ingredient').