It wont damage your system.
Will it work is unkown.
RAM is designed to work in pairs which is why they sell them in kits. The kits contain 2 sticks both cut from the exact same sheet of silicon that are stress tested together to make sure they are completley stable.
If you buy a single stick of ram and latter go out and buy another single stick of ram, even if the exact same model it still can have instability issues. Not to say it is garanteed, but always possible.
You can certianly buy it, and return it if unstable and then know that you need to get a full kit of ram.