It's important to cite your sources. Using someone else's idea without giving them credit is considered plagiarism and academic dishonesty. This can have serious consequences.
Fortunately, it's really easy to avoid. Cite your sources!
We are lucky in chemistry! We have our own citation style designed specifically for us. It is the American Chemical Society (ACS) citation style.
The ACS Style Guide will tell you about all aspects of writing in chemistry, not just how to format your references.
When you are using the ACS Ctation Style you will need to find the journal abbreviation if you don't have it already. The gold-standard way of finding these is to use a group of books called CASSI, (Chemical Abstracts Services Source Index). However, there are websites that can help you do this without coming in to the library to use these books.
Zotero is a freeware option for bibliographic management software. The software is an extension to your web browser.