Zotero is a free and open-source reference management software to manage bibliographic data and related research materials. Basically, Zotero collects citations of articles and resources you are viewing online.
If you have not already created a Zotero account, you can create one here.
You are not able to download the Zotero program on a Chromebook, but you can access the web version and utilize the Zotero Chrome extension. This extension has limited features, but it will enable you to save citations to your online library.
Login to Zotero online here.
Then, download the Zotero Connector Chrome extension from the Google Play Store.
Once the extension is downloaded and you are logged into your Zotero account online (Keep one tab open on Zotero.org and another for your research.), you can click the extension icon in the upper-right corner of your browser window.
After clicking the extension icon, a pop-up window will ask you if Zotero is running. Since you cannot download the app on a Chromebook, click Enable Saving to Online Library.
Your citation will then be saved into your main Zotero library and can be moved or edited by going to your Zotero online account.
If you need more of a visual representation of this, see the video below made by Wesleyan University. Please note that examples are given for students of a university other than Evergreen State College.
Hypothesis is a web and PDF annotation tool.
You will need to first sign up for a Hypothesis account and download the Google Chrome extension at https://web.hypothes.is/start/.
Once you have downloaded the extension and have logged in, click on the Hypothesis icon on the top-right of your browser window to start annotating. You can pull the annotation menu out by clicking on the arrod.
For a more visual representation of this browser extension, please view the below video from Hypothesis.