Is the f5 pawn isolated?
No it's not isolated, as there is a pawn on the g-file (doesn't matter if it's not connected to the f5-pawn, or it's in front, or backward). The idea of isolated pawns is permanent (can't be changed by pushing pawns) - an isolated pawn can only be rectified by:
- getting rid of the isolated pawn (e.g. exchange it away)
- a pawn capture on a file next to the isolated pawn so that there is now a pawn beside it (doesn't matter which rank).