Q1) When the principal quantum number is 2, what can ms be?
1) -1 or 1
2) -1/2 or 1/2
3) 0 or 1
4) -2 or 2
5) 1, 0 or 0
Q2) An electron in an atom is in a state with principal quantum
number n = 4. The possible values of the orbital quantum number
ℓ are:
1) 1, 2, 3
2) 1, 2, 3, 4
3) -3, -2, -1, 0, 1, 2, 3
4) 0, 1, 2, 3
5) 0, 1, 2
Q3) A hydrogen atom is in a state for which the principle
quantum number is n = 3. How many possible states are
there for which the magnetic quantum number is ml = 0?
1) 2
2) 4
3) 6
4) 8
5) 10
Q4) Which of the following (n, ℓ , mℓ , ms) combinations is
impossible for an electron in an atom?
1) 3, 1, 1, -1/2
2) 6, 2, 0, 1/2
3) 3, 2, -2, -1/2
4) 3, 1, -2, 1/2
5) 1, 0, 0, -1/2
Q5) An excited hydrogen electron is in the principal shell n = 3.
Which of the following is a possible set of quantum numbers
(n, l, ml, ms) for the electron's state?
1) 3, 2, -3, 1/2
2) 3, 3, 2, -1/2
3) 3, 1, 2, 1/2
4) 3, 2, -2, -1/2
5) none of the above
Q6) A subgroup of hydrogen atom states within the n = 5 group
has l = 3. How many values of ml are possible for states within this
subgroup?
1) 5
2) 6
3) 7
4) 8
5) 9
Q7) How many electron states (including spin states) are possible
in a hydrogen atom if its energy is –3.4 eV?
1) 2
2) 4
3) 6
4) 8
5) 10
Q8) Determine the maximum number of electron states with
principal quantum number n = 3?
1) 2
2) 3
3) 6
4) 9
5) 18
Q9) The total number of electron states with n = 2 and ℓ = 1 for an
atom is:
1) two
2) four
3) six
4) eight
5) ten
Q10) The Pauli exclusion principle is obeyed by:
1) all particles
2) all charged particles
3) all particles with spin quantum numbers of 1/2
4) all particles with spin quantum numbers of 1
5) all particles with mass
Q11) Radiation with the minimum wavelength as well as the K x-ray lines
are detected for a certain target. The energy of the incident electrons is
then doubled, with the result that
1) the minimum wavelength increases and the wavelengths of the K lines
remain the same
2) the minimum wavelength decreases and the wavelengths of the K lines
remain the same
3) the minimum wavelength and the wavelengths of the K lines all
increase
4) the minimum wavelength and the wavelengths of the K lines all
decrease
5) the minimum wavelength increases and the wavelengths of the K lines
all decrease
Q12) Two different electron beams are incident on two different
targets and both produce x rays. The cutoff wavelength for target 1
is shorter than the cutoff wavelength for target 2. We can conclude
that:
1) target 2 has a higher atomic number than target 1
2) target 2 has a lower atomic number than target 1
3) the electrons in beam 1 have greater kinetic energy than those in
beam 2
4) the electrons in beam 1 have less
Q13) A photon with the smallest wavelength in the continuous xray spectrum is emitted when:
1) an electron is knocked from a K shell
2) a valence electron is knocked from the atom
3) the incident electron becomes bound to the atom
4) the atom has the greatest recoil energy
5) the incident electron loses all its energy in a single decelerating
event
Q14) A fluorescent substance absorbs photons with a wavelength
1 and then emits photons with a wavelength 2. Which of the
following is possible?
1) 1 = 2, because energy is conserved in the process.
2) 1 < 2, because intermediate energy levels are available.
3) 1 > 2, because intermediate energy levels are available.
4) both a and b
Q15) Which of the following is essential for laser action to occur
between two energy levels of an atom?
1) the lower level is metastable
2) the upper level is metastable
3) the lower level is the ground state
4) there are more atoms in the lower level than in the upper level
5) the lasing material is a gas
Q16) A metastable state is important for the generation of a laser
beam because it assures that:
1) spontaneous emission does not occur more often than stimulated
emission
2) photons do not split too rapidly
3) more photons are emitted than are absorbed
4) photons do not collide with each other
5) photons do not make upward transitions
Q17) How many of the following are essential for laser
action to occur between two energy levels of an atom?
(a) There are more atoms in the upper level than in the
lower. (b) The upper level is metastable. (c) The lower level
is metastable. (d) The lower level is the ground state of the
atom. (e) The lasing medium is a gas.
1) 1
2) 2
3) 3
4) 4
5) 5
Q18) In a laser:
1) excited atoms are stimulated to emit photons by radiation
external to the laser
2) the transitions for laser emission are directly to the ground state
3) the states which give rise to laser emission are usually very
unstable states that decay rapidly
4) the state in which an atom is initially excited is never between
two states that are involved in the stimulated emission
5) a minimum of two energy levels are required.
Q19) Shown are possible electron states for a ruby laser. Which
arrow(s) indicate energy transitions that cause emission of a
photon?
1) b only
2) b and d
3) b, d, and f
4) f only
Q20) Shown are possible electron states for a ruby laser. Which
arrow(s) indicate the energy transition due to stimulated emission
of a photon?
1) b
2) d
3) b and f
4) f