# How fast do electrons move in an electric arc?

I know that they move extremely slow in wire, http://www.youtube.com/watch?v=jbi7gJTPSXk) but how fast do electrons move in air in an electric spark/arc?

• To be fair, the communication speed is high because the effective collision rate is high? So while their bulk drift speed is low, that they almost constantly bump into each other allows them to transmit information at much larger speeds. It's similar to pushing on the end of a rigid rod (very loose analogy). – honeste_vivere Feb 17 '17 at 14:28
• Is there anywhere where I can find out what the speed is at various voltages, such as ten kilo volts? – Maxwell Baker Feb 17 '17 at 18:11
• also is there any chart that show how magnetic fields would change the speed. – Maxwell Baker Feb 17 '17 at 18:12
• I just noticed a punctuation error/typo. The first sentence should end with a period, not question mark. – honeste_vivere Feb 17 '17 at 18:20

The speed of electrons in metals is actually very high, around $10^5 ms^{-1}$. It is the drift velocity which is very slow, about $1mms^{-1}$. The electrical signal in the wire travels close the speed of light at about $10^8ms^{-1}$. See velocity of free electrons in a wire.
You need to specify the conditions in the arc. An electron accelerated through a potential difference of $300V$ has a speed of about $10^7ms^{-1}$.