There are 2
There are 7 non-event islands.
I've tried getting there in Crystal version, the Seafoam Islands were nowhere to be found even when I was apparently RIGHT where they should be. I'm guessing you can't, however, since many things from GSC are being changed in the remake, maybe they will be there
hmmm... you can catch almost all kanto hmm and after u unlock the extra islands you can catch many more...
there are 151 between leafgreen and fire red
150
Articuno is found in the Seafoam Islands. The Islands are like a huge maze, so make sure you bring many repels. Articuno is located on the level with water. Continue making your way around the cave within the islands until you find it.
Only 1.
In total including event only Pokemon there are 10.
Only one
Of the many Pokemon that you can't get in leafgreen are: Ekans, Poliwag, Scyther, Delibird, Oddish, Murkrow, Growlithe and many more. Edit: Poliwag can be found using a super rod in the pond at route 6.
wow there are so many noob questions these days well ill still answer it you need to go to the town with the ferry or whatever and if you have the second pass you can go to all the islands P.S. you nooooooob there is no island 8!
5Moltres (mt. ember (island 1))Zapados (power plant (below rock cave (use surf to get it)))Articuno (seafoam islands (on the way to cinnabar island))Mewtwo (cerulean cave (you need to have beaten the elite four and given the ruby and sapphire to Bill's friend (also to trade with other games)))Entei, Raikou, or Suicune (encountered randomly) (if u got: Bulbasaur - Entei, Squirtle - Raikou, or Charmander - Suicune)