Removing a key binding

How can I remove a (globally set) key binding? My emacs binds set-mark-command to C-@,开发者_StackOverflow C-SPC, and M-SPC by default, and I want to free C-SPC from it without assigning something else within emacs so that I can use that for a keyboard shortcut defined in the OS.

Does global-unset-key do the trick?