You can't trade between every single version of Pokémon.
You can trade between Pokémon Red, Blue, Yellow, Gold, Silver, Crystal and for the Japanese-only release of Pokémon Green.
You can trade between Pokémon Ruby, Sapphire, FireRed, LeafGreen and Emerald.
You can trade between Pokémon Diamond, Pearl, Platinum, HeartGold and SoulSilver.
You can trade between Pokémon Black and White.
in short, you can only trade and battle within generations. so black and white 2 will theoretically be able to trade/battle black and white. you can get pokemon across generations with pal park and poke transfer but you cannot trade over held items.
Chat with our AI personalities
No, you cannot trade between the two different versions because the Pokemon are different or the Pokemon know different moves that are not in red version. When they re-make gold and silver for DS there may be some way to trade between Pokemon fire red and leafgreen to the new gold and silver but I doubt it.
They should be able to trade.
yes
No.
yes, but not to any of the old games, only between other silver versions, gold versions, or crystal versions.