Zapdos does not learn zap cannon via level up or through any other means in Generation IV.
It used to be able to learn it via TM in Gen II, so I suppose you could trade one from there if possible
It does not learn it by leveling up in the Heartgold/Soulsilver versions. But by finding TM 57 you can teach Zapdos Charge beam,you can buy it at goldenrod department store. You can also find it by giving the missing machine piece to the owner of the power plant. It cannot learn it by leveling up in fire red, leaf green, diamond, pearl, or platinum version. It can learn charge by leveling up. Hyper beam can be taught through a tm.
feraligatr learns hydro cannon at level 74
I think you have to use a TM on him.
nothing, but it learns drill peck at 71 and thunder at 78.
He is in soulsilver after you get all 16 gym badges go to the powerplant in Kanto and there you will see him. He is at level 50 so get his HP as low as possible. Put him to sleep the get out your strongest Pokemon and use a level ball (Made by Kurt). If you don't have a level ball the use a lot of ultra balls. After 20 turns if you haven't caught Zapdos then use a timer ball because it will be twice as strong as a Ultra ball.
Zapdos doesn't learn it by leveling up. You buy or find TM24(Thunderbolt) and then teach it to Zapdos.
level 85
Ampharos cannot learn Zap Cannon.
It does not learn it by leveling up in the Heartgold/Soulsilver versions. But by finding TM 57 you can teach Zapdos Charge beam,you can buy it at goldenrod department store. You can also find it by giving the missing machine piece to the owner of the power plant. It cannot learn it by leveling up in fire red, leaf green, diamond, pearl, or platinum version. It can learn charge by leveling up. Hyper beam can be taught through a tm.
Look here: http://bulbapedia.bulbagarden.net/wiki/Zapdos(Pokémon)#Learnset
Zapdos will not learn many moves, but here are a few moves such as: Charge on level 61 Light Screen on level 73 Thunder at level 85 Hyper Beam by TM15 Shock Wave by TM34 Hope this helped you and your Zapdos!
feraligatr learns hydro cannon at level 74
Level 22
*
Level 64.
Bayleef Does Not Learn Sleep Powder in HeartGold/SoulSilver
i think magneton learns zap cannon at level 53 or 57