Assume a stellar atmosphere of pure helium. (a) find i at t=15,000k. assume ni the electron pressure in the atmosphere is pe 20 n /m2. calculate how this would change for t 5,000k and t 25,000 k. helium has two electrons and so can be doubly ionized, he iii. (b) what is nat t-15,00ok. calculate how this would change for t = 5,000k and t 25,000 k. (c) how does l compare to as the temperature changes? describe why this occurs ni