OED Definition (1): The branch of science concerned with the substances of which matter is composed, the investigation of their properties and reactions, and the use of such reactions to form new substances; (in early use also) alchemy. (1)
Chemistry is the science of substance. It studies the things that, a lot of the time, we can see but does not make up a whole living organism. Occasionally this will have elements smaller than that which can be seen with a microscope. But otherwise it teaches us how to make alcohol, what dissolves in acid and why some things go boom.
The main subjects will include:
- Organic chemistry (alcohol and fuel).
- Inorganic chemistry (metallurgy, acids and explosions).
- Analytical chemistry (how to see what atoms something’s made of, including the origins of an MRI scanner)