Does anybody know if the Arduino Uno can power two 9v LED?
ok, can you please tell me.. YES you can or NO you can't....
I don't want to buy them if I can't use them...
Yes I know.
EDIT modifying the original question after the first answere is bad form and what is more ruins the joke.
Next time get the question right first time.
If you provide a link to the part we could tell you how to control it with an arduino.
Yes, I can confirm that Mike knows the answer!
So in short, Arduinos operate on a Vcc of 5V - unless they are the 3.3V version. You specified a 9V LED, so this should be self-evident.
What we want to know is - what on earth is a 9V LED, let alone two of them? If you are referring to an illuminant - a LED light fitting of significant power; 10 watts or more - then you will be needing a constant-current, generally switchmode regulator which may already have a control input but will be operating from a suitable power supply, probably 12V or more and not the same one that is powering the Arduino.