How to Kill an Unresponsive Application on Ubuntu 18.04 LTS?br br Step 1: Click on 'Show Applications' at the bottom left.br br Step 2: Do a Search for 'System Monitor,' and then click on it to open it.br br Step 3: Click on the 'search' button, search for your unresponsive application.br br Step 4: Select it by clicking on it, right click on that.