The energy the electron gives up passing between the electrodes is equal to the product between its charge and the potential difference between the electrodes:

where
e is the electron charge

is the potential difference
Plugging numbers into the equation, we find that the electron gives up is
Answer:
Candles
Explanation:
The answer is the first option or "candles." In ancient times the people would lit candles and place them in difference places in their homes, temples, etc... to produce light. It's not option B because light emitting diodes are used to light up toys and such which weren't invented in ancient times. It's not option C because fluorescent bulbs are long light bulbs used to light up huge spaces without as many light bulbs which were again not invented at the time, and it's also not option D because incandescent bulbs are you usual light bulbs which weren't invented at the time.
Hope this helps.
Answer:
0.582 MeV
2.45 MeV
Explanation:
=Electron rest energy
(a) 0.500c to 0.900c

Energy required is 0.582 MeV
(b) 0.900c to 0.990c

Energy required is 2.45 MeV