We won't know that until we are sure that we have discovered all of them.
which exoplanet is 'THE exoplanet'?
The largest known planet is WASP-17b, is an exoplanet in the constellation scorpius,with diameter of 300,000 km its more than twice the size of jupiter
The darkest exoplanet is "TRES-2B".
No. An exoplanet is a planet outside of our Solar System.
51 Pegasi itself isn't an exoplanet, it's a Sun-like Star. But it does have an Exoplanet orbiting it, 51 Pegasi b (informally named Bellerophon.).
No. A moon is not a planet. An exoplanet is aplanet that orbits a star other than the sun.
Both exoplanet and extrasolar planet are planets that are outside the solar sysytem.
Yes. While we know relatively little about the atmospheres of individual expolanets, there is no reason an exoplanet couldn't have an exosphere.
We do not know enough about conditions on any exoplanet to determine if any would be suitable for humans.
yes
extra-solar planet.
no cheat's. xD