Question

what causes the fluoresent tubes and neon bulb to glow​

Answer 1

Answer:

When an application of high voltage is provided to the electrodes, the neon gas ionizes due to the flow of e− which thereby excite the neon gas atoms and cause them to emit light. In the case of fluorescent tubes, low-pressure mercury vapour is present which emits UV light when ionized.

Answer 2

Answer:

When an application of high voltage is provided to the electrodes, the neon gas ionizes due to the flow of e− which thereby excite the neon gas atoms and cause them to emit light. In the case of fluorescent tubes, low-pressure mercury vapour is present which emits UV light when ionized.