When Chrome crashes or freezes, the first thing you should do is restart it completely. To do so, select Exit from the three-dot Menu button in Chrome's top-right corner. Then, after a few moments, reopen Chrome to see if the problem has been resolved.
Chrome can continue to run in the background if you simply click the X in the upper corner. Go to Menu > Settings to turn this off. To see more settings, scroll down and select Advanced, then scroll all the way down to the bottom to the System section. Disable it here. If you want Google Chrometo close entirely when you click the X in its window, keep running background apps while it's closed.
Next, take a look at how many tabs you have open in Chrome. Websites may crash if your computer's RAM is low (which is often the case owing to Chrome's high memory usage). Close any tabs you're not using, pause any Chrome downloads, and shut down any programs you don't need running on your computer.
To help with this, launch Chrome's task manager by pressing Shift + Esc. This will show you a rundown of everything running in Chrome, allowing you to shut off the most resource-intensive users. If none of the following solutions appear to work, restart your computer. Rebooting your computer, as you surely know, can resolve a variety of difficulties, including any temporary Chrome troubles.
Finally, navigate to Menu > Help > About Google Chrome to see if there are any Chrome updates available. Bugs can be fixed in the next versions.