Rydberg

[006033476]

The electron in a hydrogen atom makes a transition from the fourth to the
second principal quantum level. Is light emitted or absorbed? Calculate the wavelength
of this light.

for this question, I am confused as to when calculating the H atom, why is RH= 2.179x10^-18 J. can someone explain the reasoning behind it?

[Sai Alapati 3K]

RH is equalled to 2.179x10^-18 because you are multiplying two constants. The Rydberg constant(R), which is 3.29x10^15 hz, and the Planck's constant, which is 6.626x10^-34 joules/hz. This gives you the number 2.179x10^-18 which is in terms of joules as the hertz cancel out and this makes sense since we are using the Rydberg equation to find a value of energy for a certain energy level.