Giesler Tubes Experiment Flashcards
what was the aim of this experiment?
to investigate the effect of different gas pressures on an electric discharge passing through a series of discharge tubes
what appeared at 40mm of Hg
a purple streamer linked to cathode to the anode
what appeared at 10mm of Hg?
the purple streamer formed a mauve positive column, seperated from the cathode via faradays dark space
what appeared at 6mm of Hg?
the positive column became pink and shortened in length
a voilet negative glow appeared near the cathode still seperated from the positive column via faradays dark space
what appeared at 3mm of Hg?
the cathod becomes covered with a red cathode glow
the negative glow is seperated from this cathode glow via a new dark region, crookes dark space
faradays dark space still seperates the positive column from the negative glow
positive column broken up into several bright striations- button shaped with their convex side facing the cathode and are reguarly spaced
what appeared at <0.1mm of Hg?
the straited positive column shortens and eventually disappears
width of the crookes dark space increases while the negative glow grows in size, travelling toward the anode
eventually the negative glow fills the entirity of the tube emitting a greenish glow
what were safety hazards and subsequently safety precuations involved in this investigation?
- high voltage sparks which can burn skin and inflict harm –> teacher operated the apparatus infront of the class
- high voltage sparks emit high energy x-rays which may cause radiation poisoning –> 3m exclusion zone was established between the apparatus and the class to minimise radiation exposure
