Please give me a helping hand on Chemistry?

Question

Please please help me on my chemistry homework, I've been looking at this question for an hour and I still can't figure this out. I've put it in some formula but it came out all werid. Please give me a hand.


5) A Certain line in the spectrum of atomic H is associated with the electronic transition of the electron from the sixth energy level (n=6) to the second energy level (n=2)

A. Indicate whether the H atom emits energy or whether it absorbs energy during the transistion. Justify your answer.
B. Calculate the wavelength, in nm, of the radiation associated with the spectral line.
C. Account for the observation that the amount of energy associated with the same electronic transition (n=6 to n= 2) in the He 1+ ion is greater than that associated with the corresponding transition in the H atom.

Thank you sooooo much!!

Answer 1

Hey this is a very good problem in chemistry though it falls under physics for more practical purposes but you might be dealing it in chemistry, ill try to help as much as i can though i left studying chemistry and physics almost 5 years back:

A.
As the electron transition is taking place from a higher energy level ( n = 6 ) to a lower energy level ( n = 2 ) so it will emit enrgy in forms of photons which compenstates the total energy difference between the two levels.

B.
In the Bohr Model and in the hydrogen spectrum:

you can calculate the wavelength by :

lambda = 9.12 *10^-8( 1/ni^2 - 1/nf^2)

Please check the following link for the formula : http://www.usm.maine.edu/~newton/Chy251_253/Lectures/BohrModel/BohrEquation3.GIF

For the transition from ni = 6 to nf = 2,
change in E (difference in initial n final )= - 4.84 x 10-19 J.

The negative sign indicates that the energy of the final state is less than that of the initial state. Converting this value of E into a wavelength yields l (lambda) = -4.10 x 10 -7 meters or 410 nm. Light of this wavelength is purple. We have ignored the negative sign since the value of l (lambda) must be positive.

C.
I reviewed a lot of papers and found out that it does not matter which one-electrom atom you are dealing with the same transition leads to similar discharge of energy , i did not find any contradicting equations either ,
check out this link for furtehr clarification:

http://www2.yk.psu.edu/~jhb3/cotw07.htm

the energy of an electron in any shell or subshell of a one-electron atom (H) or ion (He+ , Li2+ , etc.) is completely determined by the quantum number n.


I hope this helps you as i spent a lot of time to deal with this problem.

Have a good day :)