In Mossdeep City.
NOTE:
If you need help with that one, Wingull and Duskull are your best options. Neither of them is affected by Claydol's killer Earthquake, and Wingull can get rid of Claydol while Duskull takes down Xatu and/or Lunatone.
keep using phychic
Psychic, and if you're talking about the gym leader from Hearthome City that uses Ghost Pokemon, then no.
Defeat Giovanni In The Sliph Co. And It Is Gonna Be Unlocked.
in D/P there isn't one. on the rest I don't think there are
See the warp panels in the gym? Use them to reach the gym leader she can be tough just depending on what Pokemon you have trained so far. Her Pokemon are weak against physical attacks like Strength, Shadow ball and many more so use them to your advantage.
The water Pokemon gym leader is in Pastoria City.
were is the fifth gym leader
You use your strong(est) Pokemon to kill the Gym Leader's Pokemon.
In Pokemon platnium it is wake gym leader. P.S. he has water type Pokemon.
the gym leader volkner uses electric Pokemon
The 8th gym leader is Drayden he uses Dragon type pokemon
You first must make sure that the gym leader is in the gym, because in some games you have to locate the gym leaders first. After that, you may have to get through a puzzle in the pokemon gym to get to the gym leader at the end of the puzzle. After that, you will battle the gym leader, and if all of her Pokemon faint, then you will probably be given a gym badge.