What is the difference in energy (in joules) between the n=5 and n=4 states of a hydrogen atom? (answer to 3 sig figs)

Answer 1

∆E = R_H (1/n_f² - 1/n_i²)

∆E = change in energy = ?

R_H = -2.179x10^-18 J (a constant)

n_f = final energy level = 4

n_i = initial energy level = 5

∆E = -2.179x10^-18 J (1/16 - 1/25) = -2.179x10^-18 J (0.0625 - 0.04)

∆E = -2.179x10^-18 J (0.0225)

∆E = -4.90x10^-20 J (only reason for negative sign is if the electron went from n=5 to n=4, otherwise it would be positive going from n=4 to 4=5)