Yes, if you install Chia using the command line method, you’re just cloning the folder from Chia’s Github repo to your home directory. Therefore deleting the chia-blockchain folder in your home directory should do the trick.
However, if you use the installer which is the more preferable method since you also get the icon launcher, you will not have chia-blockchain folder in your home directory. Chia will install in your system much like on Windows with exactly the same folder structure. You can uninstall it by using Ubuntu Software Center or Synaptic Packages Manager.