Sample Exam IV

1. The Heisenburg uncertainty principle implies that the energy and time can be accurately determined
at the same time. What is the truth about this statement?

a. It is true as stated. b. It is true only if your experiments are not perfect.
c. It is true if the particles are not waves. d. It is definitely not true.

2. The wave-particle duality refers to the fact that--------can exhibit both wave and particle characteristics.
a. light b. matter c. both light and matter d. nothing

3. Which of the following is not a feature of the Bohr model of the atom?
a. a small, positively charged nucleus. b. electrons in planetary-like orbits.
c. quantized energy levels. d. an electron probability cloud.

4. According to the Pauli exclusion principle,
a. electrons are excluded from entering the nucleus.
b. electrons must exist in discrete energy states.
c. no two electrons can have the same set of values for the four quantum numbers.
d. electrons cannot be removed from an atom.

5. The number of electrons that can be accommodated in a 3p subshell is
a. 6 b. 14 c. 18 d. 26

6. The atom radiates when an electron jumps from
a. n=1 to n= 2 b. n=1 to n=0 c. n=2 to n=1 d. n= 3 to n=4

7. How many possible states are there for n=6?
a. 18 b. 36 c. 26 d. 72

1. Write down the ground state electronic configuration for Uranium Z= 92

2. Light of 410.2 nm wavelengths is emitted from a hydrogen discharge tube. If the transitions that produces
this emission occurs to the nf = 2 level, from which level ni did it originate?

3. A hydrogen atom is in its first excited state n=3. Using the Bohr theory of the atom, calculate
(a) the potential energy of the electron (b) the kinetic energy of the electron.

4. Assume that position of an electron is known so precisely that the uncertainty in the position is
only 1.5x10^-11 m. Determine the minimum uncertainty in the speed of the electron. (Mass = 9.1x10-31 kg)

5. What is the de Broglie wavelength of a 3.5 g bullet traveling with a speed of 600 m/s?