Out of all silver halides, AgBr is most sensitive to light and under goes photo reduction to metalic silver instantaneously on exposure to light.
`2AgBrto2Ag+Br_(2)`
Unexposed AgBr can be dissolved out in h ypo `(Na_(2)S_(2)O_(3))` solution.
`AgBr+2Na_(2)S_(2)O_(3)toNa_(3)[Ag(S_(2)O_(3))_(2)]+NaBr.`
