The best way to learn proper English is to read news report, and watch news on TV. Watching TV shows is a great way to learn casual English, slang words, understand culture reference and humor. If you have already watched these shows then you may recall the words used in the following dialogs.

Also in the CHEMICAL industry,
Money Heist Season 1, Episode 12

Has a strong toxic
CHEMICAL smell.
The Big Bang Theory Season 5, Episode 2

is the power to transmute
CHEMICAL elements.
The Big Bang Theory Season 7, Episode 3

What?
It's losing its CHEMICAL potency.
Breaking Bad Season 2, Episode 9

lt's filled with scientific formulas
and CHEMICAL purchase lists,
Breaking Bad Season 4, Episode 3