Page 150 - Bruno Linder Elementary Physical Chemistry

August 18, 2010 11:37 9in x 6in b985-appA Elementary Physical Chemistry

Appendix A: Homework Problem Sets 135

6. What is the energy of radiation corresponding to the following wave-
length: (a) 650 nm (red), (b) 450 nm (violet), (c) 150 pm (X-rays)?
7. The work function of a metal is 2.0 eV. If the metal is subjected to
radiation of wavelength (a) 250 nm, (b) 700 nm, will an electron be
emitted, and if so, what will be the kinetic energy of the emitted
electron?
8. Calculate the de Broglie wavelength of
(a) a particle of mass of 1 g traveling with a speed of 2.0 ms −1 ,
3
(b) a He atom traveling with a speed of 10 ms −1 .
9. What is the frequency of the transition of line n =6
(a) in the Balmer series?
(b) in the Paschen series?
10. The probability of finding the electron in the H-atom in a small volume
element at a radius r is 40% of its maximum value. Calculate the
radius r.
11. Which of the following electronic transitions in an atom are allowed?
which are forbidden? Why?
(a) 3s → 2s, (b) 2p → 1s, (c) 4d → 3p, (d) 3d → 2s, (e) 5p → 2s.

12. How many electrons can occupy a subshell whose value is

(a) l = 0, (b) l = 2, (c) l = 4. Explain.

13. The wavelength λ =6.577 × 10 −5 cm is observed in the spectrum of H.
Show that this is a transition line in the Balmer Series. What is the
wavelength of the next higher line?

Problem Set VII. Chapters 10, 11, 12
1. Give the ground state electron configuration of

(a) H 2 , (b) Li 2 , (c) C 2 , (d) N 2 , (e) O , (f) F .
2 2
2. Which of the molecules in Problems 1 would you expect to be stabi-
lized by
(a) the addition of an electron?
(b) the removal of an electron? Explain.