No you cannot trade Pokemon from Pokemon Emerald to Pokemon Crystal. Pokemon Crystal can only trade with Red, Green, Blue, Yellow, Gold, Silver and other Pokemon Crystal games. The only restriction with trading between Crystal and the 1st Generation of games is that you can only trade to 1st gen if the Pokemon is from Kanto and doesn't have a 2nd gen item on it for obvious reasons as well as doesn't have one of the newly-created 2nd Generation moves.
You can however trade Pokemon from Pokemon Emerald over to other Pokemon Emerald games as well as to and from Pokemon Ruby, Pokemon Sapphire, FireRed and LeafGreen.
You can also send Pokemon from Emerald (along with Ruby, Sapphire, FireRed and LeafGreen) over to Diamond, Pearl, Platinum, HeartGold or SoulSilver but it's a 1-way transfer feature that is called migration. You can send over the Pokemon you want in your 3rd Gen game over to one of the 4th Gen games and it will be uploaded into Pal Park. Pal Park is just a park where the Pokemon go and you have to catch them like a normal wild Pokemon.
No there is no way of transfering from Crystal to Emerald. Only RBY to GSC, and Emerald to all games beyond.
No
yes, but you how to have some kind of cord to trade.
You can only trade it from another game: Gold, Silver, Crystal or Emerald.
You can only trade it from another game: Gold, Silver, Crystal or Emerald.
No, Pokémon Crystal is not capable of communicating with Pokémon Emerald.
No, it is impossible to trade from crystal to ruby/saphire/emerald. The games are incompatible.
Sadly you can't. You can trade From Yellow to : Red, Blue, Green, Gold, Silver and Crystal. From LeafGreen you can trade to : FireRed, Ruby, Saphire and Emerald.
Pokemon Emerald: Birth Island Pokemon Sapphire: Trade from Pokemon FireRed, LeafGreen, or Emerald. Pokemon Ruby: Trade from Pokemon FireRed, LeafGreen, or Emerald.
You can either get Celebi by using a cheat code or you can trade it from Pokemon Crystal after completing the GS Ball event.
all Pokemon can be traded (even eggs) to Leaf Green with out the nat. dex. with the nat dex. you can trade to emerald, ruby and Sapphire. but not to the older games like crystal and red
I assume you mean pokemon FROM gold version, and that you want to trade them to your emerald version. You can't. Emerald is a generation three game whereas Gold is a generation two game. You can only trade Emerald with Ruby, Sapphire, Firered and Leafgreen. Pokemon Gold can only trade with Crystal, Silver, Red, Blue and Yellow. If you mean actual 'Gold' pokemon, then you're talking about shiny pokemon. You need to catch them in the wild (1/+8000, so have fun with that).