[Maximum number: 4]

The diagram shows the three lowest energy levels of the hydrogen atom.

The energy of each level is indicated.

(a)

State the number of transitions between these levels that result in the emission of photons.

[ 1 ]

(b)

Calculate the largest photon wavelength for these transitions.

[ 3 ]

(a)

A stationary isotope of ${ }_{88} \mathrm{Ra}$ (Radium) decays into Rn (Radon) and an alpha particle.

[ 1 ]

(i)

Identify the proton number of Rn .

The following data are available:
Atomic mass of Ra=226.02540 u
Atomic mass of Rn=222.01757 u
Mass of $\alpha=4.00260 \mathrm{u}$

[ 1 ]

(b)

In an experiment performed by Geiger, Marsden and Rutherford to investigate the atomic structure, alpha particles were directed into a thin metal foil.

[ 4 ]

(i)

Describe two observations of this experiment.

[ 2 ]

(ii)

Outline how the experiment was interpreted.

[ 2 ]

[Maximum number: 3]

This question is about polarization.
Outline how polarization may be used in stress analysis.

This question is about atomic energy levels.

(a)

Explain how atomic spectra provide evidence for the quantization of energy in atoms.

[ 3 ]

[Maximum number: 10]

This question is about atomic energy levels.

(a)

Outline a laboratory procedure for producing and observing the atomic absorption spectrum of a gas.

[ 3 ]

(b)

(i)

Describe the appearance of an atomic absorption spectrum.

[ 1 ]

(ii)

Explain why the spectrum in (a) provides evidence for quantization of energy in atoms.

[ 3 ]

(c)

The principal energy levels of the hydrogen atom in electronvolt ( eV ) are given by

E_{n}=\frac{13.6}{n^{2}}

where n is a positive integer.
Determine the wavelength of the absorption line that corresponds to an electron transition from the energy level given by n=1 to the level given by n=3.

[ 3 ]

[Maximum number: 2]

This question is about quantum physics.

(a)

An electron is accelerated from rest through a potential difference of 5.0 kV .

[ 2 ]

(i)

Determine the energy of a photon that has the same wavelength as the electron in (b)(ii).

[ 2 ]

[Maximum number: 1]

This question is in two parts. Part 1 is about electric fields and radioactive decay. Part 2 is about change of phase.

Part 1 Electric fields and radioactive decay

(a)

Protons can be produced by the bombardment of nitrogen- 14 nuclei with alpha particles. The nuclear reaction equation for this process is given below.

{ }_{7}^{14} \mathrm{~N}+{ }_{2}^{4} \mathrm{He} \rightarrow \mathrm{X}+{ }_{1}^{1} \mathrm{H}

Identify the proton number and nucleon number for the nucleus X .

Proton number:

Nucleon number:

[ 1 ]

[Maximum number: 4]

This question is in two parts. Part 1 is about the nuclear model of the atom and radioactive decay. Part 2 is about waves.

Part 1 Nuclear model of the atom and radioactive decay

(a)

Outline how the evidence supplied by the Geiger-Marsden experiment supports the nuclear model of the atom.

[ 4 ]

[Maximum number: 1]

This section consists of three questions: B1, B2 and B3.

(a)

Tritium may be produced by bombarding a nucleus of the isotope lithium-7 with a high-energy neutron. The reaction equation for this interaction is

{ }_{3}^{7} \mathrm{Li}+{ }_{0}^{1} \mathrm{n} \rightarrow{ }_{1}^{3} \mathrm{H}+{ }_{Z}^{4} \mathrm{X}+{ }_{0}^{1} \mathrm{n} .

[ 1 ]

(i)

Identify the proton number Z of X.

Z=

[ 1 ]

[Maximum number: 3]

This question is about energy sources.

A small island is situated in the Arctic. The islanders require an electricity supply but have no fossil fuels on the island. It is suggested that wind generators should be used in combination with power stations using either oil or nuclear fuel.

(a)

The nuclear equation below shows one of the possible fission reactions in a nuclear reactor.

{ }_{0}^{1} \mathrm{n}+{ }_{92}^{\ldots} \mathrm{U} \rightarrow{ }_{\ldots}^{92} \mathrm{Kr}+{ }_{56}^{141} \mathrm{Ba}+\ldots{ }_{0}^{1} \mathrm{n}

Identify the missing numbers in the equation.

[ 3 ]

[Maximum number: 5]

This question is about energy level transitions.

Some of the electron energy levels for a hydrogen atom are shown.

(a)

A hydrogen atom is excited to the -1.51 eV level.

[ 2 ]

(i)

On the diagram, label using arrows all the possible transitions that might occur as the hydrogen atom returns to the ground state.

[ 1 ]

(ii)

State the energy in eV of the maximum wavelength photon emitted as the hydrogen atom returns to the ground state.

[ 1 ]

(b)

Monochromatic radiation is incident on gaseous hydrogen. All the hydrogen atoms are in the ground state. Describe what could happen to the radiation and to the hydrogen atoms if the incident photon energy is equal to

[ 3 ]

(i)

10.2 eV .

[ 2 ]

(ii)

9.0 eV .

[ 1 ]

Question 1

Question 1(a)

Question 1(b)

Question 3

Question 3(a)

Question 3(a)(i)

Question 3(b)

Question 3(b)(i)

Question 3(b)(ii)

Question B1

Question B1(a)

Question B1

Question B1(a)

Question B1(b)

Question B1(b)(i)

Question B1(b)(ii)

Question B1(c)

Question 4

Question 4(b)

Question 4(b)(iii)

Question 4

Question 4(d)

Question 4

Question 4(a)

Question B1

Question B1(b)

Question B1(b)(i)

Question 4

Question 4(f)

Question 6

Question 6(a)

Question 6(a)(i)

Question 6(a)(ii)

Question 6(b)

Question 6(b)(i)

Question 6(b)(ii)