What is electric arc..?? Difference b/w nascent and atomic hydrogen..??

While welding or solderring the fluid or plasma which gets dicharges when the two elctrodes or metals are higly brought together.

The gases b/e them gets ionised and are thus visible. 

@ simran 
the nascent and the atomic hydrogen both are actually same , usually hydrogen exist as a diatomic molecule , bonded by covalent bond , hydrogen obtained by disolution of this bond is called as atomic hydrogen . 
atomic hydrogen released during chemical reaction is called as nascent hydrogen . 
2- an electric arc is a visible plasma discharge between two electrodes that is caused by electrical current ionising gases in the air . electric arc occur in nature in the form of lightning . 
HOPE IT CLEARS YOUR DOUBT 

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