In Davisson-Germer experiment, electron gun is coated with oxide of_______ . (A) Barium (B) Sodium (C) Potassium (D) Iron

a: a Davidson and Gemmer's experiments included nickel crystals ( targets ), electronic guns and detectors.The electronic gun consists of tungsten wire and high and low battery.The function of uncoated tungsten wire is.4.5 eV.The barium oxide coating on this filament reduces its working function, allowing electrons to be emitted at low temperatures.