I'm just curious what happens when you desolder the led on the arduino board.......and then solder it back on (will it work) and can you take the Atmega chip out of the socket
can you take the Atmega chip out of the socket
Yes, I do it all the time.
what happens when you desolder the led on the arduino board.......and then solder it back on (will it work)
It depends on how good you are at desoldering. It is a surface mount device that could be destroyed if you are not careful. Fine jets of hot air are the best.
But why would you want to remove it and then re solder it? If it needs to be removed you are best thinking it is going to be disposed of and a new one soldered in it's place. That way you can remove it with a minimum of track damage.