To retrieve an accidentally closed tab, press Command+Shift+T or navigating to File > Reopen Closed Tab. And, if you press Command+Shift+T again (or File > Reopen Closed Tab), it will open the second last closed tab and so on.
But what if you had a bunch of tabs open and you accidentally closed out of your Chrome browser? Again, it is easy to get back to where you were. Open your browser and navigate to History > Recently Closed > Tabs > Restore All Tabs
For students that you are monitoring computer use or are suspicious that they closed something quickly as you walked by, you can hit Command+Shift+T and this will reopen the most recently closed tab. This will only work for Chromebooks and during one signed in session.
