Topic 7.1 [26 marks]
1.
Which statement about atomic spectra is not true?
[1 mark]
A. They provide evidence for discrete energy levels in atoms.
B. Emission and absorption lines of equal frequency correspond to transitions between the same two energy levels.
C. Absorption lines arise when electrons gain energy.
D. Emission lines always correspond to the visible part of the electromagnetic spectrum.
2.
Atomic spectra are caused when a certain particle makes transitions between energy levels.
[1 mark]
What is this particle?
A. Electron
B. Proton
C. Neutron
D. Alpha particle
3.
Photons of energy 2.3eV are incident on a low-pressure vapour. The energy levels of the atoms in the vapour are shown
[1 mark]
What energy transition will occur when a photon is absorbed by the vapour?
A. –3.9eV to –1.6eV
B. –1.6eV to 0eV
C. –1.6eV to –3.9eV
D. 0eV to –1.6eV
4.
A simple model of an atom has five energy levels. What is the maximum number of different frequencies in the emission spectrum [1 mark]
of that atom?
A. 4
B. 6
C. 10
D. 25
5.
A simple model of the hydrogen atom suggests that the electron orbits the proton. What is the force that keeps the electron in
[1 mark]
orbit?
6.
A.
Electrostatic
B.
Gravitational
C.
Strong nuclear
D.
Centripetal
What is the relationship between nucleon number A, proton number Z and neutron number N?
[1 mark]
A. A=Z=N
B. A+Z=N
C. A−Z=N
D. Z−A=N
7.
Some of the energy levels for a hydrogen atom are shown in the diagram.
[1 mark]
The table shows four photons with their corresponding energies.
Each photon is incident on a hydrogen atom in its ground state. Which photons could be absorbed by the atom?
A. W only
B. X and Y only
C. Y and Z only
D. X, Y and Z only
8a. This question is about the hydrogen atom.
[2 marks]
The diagram shows the three lowest energy levels of a hydrogen atom.
An electron is excited to the n=3 energy level. On the diagram, draw arrows to show the possible electron transitions that can lead to the
emission of a photon.
8b. Show that a photon of wavelength 656 nm can be emitted from a hydrogen atom.
9.
In a neutral atom there are ne electrons, np protons and nn neutrons. What is the mass number of the nuclide?
[2 marks]
[1 mark]
A. np + ne + nn
B. np + nn
C. nn + np – ne
D. nn – ne
10a. This question is about atomic spectra and energy states.
Outline how atomic absorption spectra provide evidence for the quantization of energy states in atoms.
[2 marks]
10b. The diagram shows some atomic energy levels of hydrogen.
[1 mark]
A photon of energy 2.86 eV is emitted from a hydrogen atom. Using the diagram, draw an arrow to indicate the electron transitions that
results in the emission of this photon.
11. Which of the following provides evidence for the existence of atomic energy levels?
A. Absorption spectra
B. Nuclear fission
C. The Geiger–Marsden experiment
D. Radioactive decay
[1 mark]
12. The arrows below indicate transitions involving three energy levels of an atom. The wavelength of the photon emitted in each
[1 mark]
transition is indicated.
Which of the following relationships between the wavelengths is correct?
A. λ 1 = λ 2 + λ 3
B. λ 1 = λ 3 − λ 2
C.
D.
1
λ1
1
λ1
=
=
1
λ2
1
λ2
+
−
1
λ3
1
λ3
13. The diagram shows four energy levels W, X, Y and Z of an atom.
[1 mark]
Which electron transition will produce a photon of the longest wavelength and which transition will produce a photon with the highest
frequency?
14a. This question is about atomic spectra.
Explain how atomic line spectra provide evidence for the existence of discrete electron energy levels in atoms.
[3 marks]
14b. The diagram shows some of the energy levels of a hydrogen atom.
(i)
Calculate the wavelength of the photon that will be emitted when an electron moves from the –3.40 eV energy level to the –13.6 eV
energy level.
(ii)
[5 marks]
State and explain if it is possible for a hydrogen atom in the ground state to absorb a photon with an energy of 12.5 eV.
© International Baccalaureate Organization 2019
International Baccalaureate® - Baccalauréat International® - Bachillerato Internacional®
Terms and conditions (https://www.ibo.org/en/terms-and-conditions/) | Privacy policy (https://www.ibo.org/terms-and-conditions/privacy-
policy/)
Printed for Moscow Economic School