There are 4 classic trade-evolution Pokemon that appear in almost all games. Those are Machoke, Graveler, Haunter and Kadabra. Also, all the Pokemon that uses the metal coat or the King's rock to evolve has to be traded while holding that item. So Slowpoke (If you want Slowking and not Slowbro), Poliwhirl (If you want Politoad and not Poliwrath), Onix and Scyther also need trading to evolve. There might be a couple from Gen 4 that need trading, but I'm not that familiar with those. Hope this helps :)
Farfetch'd does not evolve in Pokemon HeartGold. Sorry! :)
Heart Scale does not evolve any Pokemon. You trade it to a maniac who will make Pokemon remember moves. In black and white, the maniac is in Mistralton city.
hitmonchan cant evolve
Wooper will evolve at Level 20.
no, you have to trade them.
Must evolve it or trade it.
It won't evolve at a certain level it will evolve when it reaches max happiness during the day which you can do by winning lots of battles with trainers or wild Pokemon without fainting
after you trade it, it will evolve into a machamp
The best place to evolve a Pokemon in Pokemon Heart Gold is at Mt. Silver.
Farfetch'd is a Pokemon that does not evolve.
Farfetch'd does not evolve in Pokemon HeartGold. Sorry! :)
Heart Scale does not evolve any Pokemon. You trade it to a maniac who will make Pokemon remember moves. In black and white, the maniac is in Mistralton city.
hitmonchan cant evolve
Wooper will evolve at Level 20.
no, you have to trade them.
Magmius or honchkrow
evolve gastly.