Currently all i5 and i7 processors have 2 or 4 cores, there is even an i7 processor having 6 cores like the one listed there:
For a more complete list if available Intel processors please check this link:
How come its call an i5 with 2 cores and an i7 with 4 cores ?
Seems like an i5 should have 5 cores and i7 would have 7...
Guess that is what you get when marketing does the naming instead of engineering.