intelligent vs intelligence

the word intelligent is an adjective (describes the quality of being bright or smart)
the word intelligence is a noun (the name of the quality or of the characteristic of being bright)

For your information, this type of information is readily available in a dictionary or if you type the keyword 'intelligent' or 'intelligence' in a search engine (website) such as http://en.wikipedia.org/wiki/Intelligent
or

American Heritage Dictionary:
http://www.bartleby.com/61

Another good dictionary:

Answers.com