[Johnny010]

I am having a problem with this question in a past exam paper...I may just be being a bit of an idiot:

Show that if an H atom is in its ground state the minimum energy photon it can
absorb is 1.634_x10^-18 J.

I am using The formula:

E_n2-E_n1=hcR∞(1/n₁² - 1/n₂²)

I keep getting a different value using n1 as 0 and n2 as 1...also using 1 and 2 respectively.
What am I doing incorrectly?

[MrTeo]

There shouldn't be any problem with the Rydberg formula according to my calculations:



using:



The values for n₁ and n₂ are 1 and 2 as they're the principal quantum numbers of the first levels.

[renge ishyo]

I think the problem might be that he is using 0 for n1 and 1 for n2. Those are the lowest energy levels in the quantum mechanical quantum theory, but not the Bohr theory (where the lowest levels are n1=1 and n2=2). The equation wouldn't give the right answer with n1=0 and n2=1, so you have to use the lowest levels from the Bohr theory.

Hope this helped.

[Johnny010]

I was just being a bit of a calculator spazz...sorry but thank you XD.