What is standard hydrogen electrode?

Explanation

Standard hydrogen electrode : It is electrode in which pure and dry He) at l atm and 298 K is bubbled around a platinised platinum foil immersed in 1M HCl solution where activity of `H^(+)` ions is 1 M. It is represented as,
`H^(+)(1M)|H_(2)(g, 1"atm")Pt`