Using the System Monitor
Open the System Monitor app. In the Processes tab, scroll down the list until you find the unresponsive app.
Right click on it and select “Kill Process”. Once confirmed, this will kill the unresponsive application.
Using a keyboard shortcut
You can assign a custom keyboard shortcut to kill an application when it becomes unresponsive.
Go to “Settings -> Keyboard” and click on the “Shortcuts” tab.
Select the “Custom Shortcuts” on the left pane, and click the “+” button.
Enter “xkill” for both the name and command. Click “Apply”.
Click the “Disabled” field to assign a keyboard shortcut (say “Ctrl + alt + k”) to this command.
Now, whenever an become unresponsive, you can just press the shortcut key “ctrl + alt + k” and your cursor will become a “X”. Click the “X” on the unresponsive app and it will kill the application. That’s it.
