Question bank
Practice A-Level CAIE Physics 11 1 Atoms Nuclei And Radiation questions by syllabus topic with past-paper context, marks, difficulty and question previews on Eduninja.
Question 2
Question 2(c)
Positronium is highly unstable, and after a very short period of time it becomes gamma radiation.
Question 2(c)(i)
Describe how gamma radiation is formed from the two particles in positronium.
electron and positron interact - positron is anti-particle of electron - (pair) annihilation occurs Any two points, 1 mark each B2 mass of the electron and positron converted into photon energy B1
Question 4
A nucleus P undergoes \(\alpha\)-decay to form nucleus Q .
Question 4(a)
Complete the equation for this decay.
\({ }_{2}^{4} \alpha\) B1 \[ { }_{82}^{211} \mathrm{Q} \] B1
Question 6
Question 6(b)
Ions, all of the same isotope, are travelling in a vacuum with a speed of \(9.6 \times 10^{4} \mathrm{~ms}^{-1}\). The ions are incident normally on a uniform magnetic field of flux density 640 mT . The ions follow semicircular paths A and B before reaching a detector, as shown in Fig. 6.1. Fig. 6.1 Data for the diameters of the paths are shown in Fig. 6.2. \begin{tabular}{|c|c|} \hline path & diameter \(/ \mathrm{cm}\) \\ \hline A & 6.2 \\ B & 12.4 \\ \hline \end{tabular} The ions in path B each have charge \(+1.6 \times 10^{-19} \mathrm{C}\).
Question 6(b)(i)
Determine the mass, in u , of the ions in path B .
m=B q r / v C1
Question 30
What could not be used to create an electric current? alpha-particles beta-particles neutrons protons
C
Question 8
Question 8(a)
State what is meant by quantisation of charge.
discrete and equal amounts (of charge) B1 [1] allow: discrete amounts of \(1.6 \times 10^{-19} \mathrm{C} /\) elementary charge/e integral multiples of \(1.6 \times 10^{-19} \mathrm{C}\) /elementary charge/e
Question 8(c)
The student repeats the experiment and determines the following values for the charge on oil drops. Use these values to suggest a value for the elementary charge. Explain your working. elementary charge = ..... C
elementary charge \(=1.6 \times 10^{-19} \mathrm{C}\) (allow \(1.6 \times 10^{-19} \mathrm{C}\) to \(1.7 \times 10^{-19} \mathrm{C}\) ) M0 either the values are (approximately) multiples of this or it is a common factor C1 it is the highest common factor A1
Question 33
An atomic nucleus emits a \(\beta\)-particle. What change does this cause to the proton number and the nucleon number of the nucleus?
D
Question 6
Question 6(a)
Describe the main principles of the determination of the charge on an oil drop by Millikan's experiment. You may draw a diagram if you wish.
oil drop charged by friction/beta source between parallel metal plates plates are horizontal adjustable potential difference/field between plates until oil drop is stationary B1 \(m g=q \times V / d\) B1 symbols explained oil drop viewed through microscope m determined from terminal speed of drop (when p.d. is zero) (any two extras, 1 each)
Question 6(b)
In an experiment to determine the fundamental charge, values of charge on oil drops were found by a student to be as shown below. State the value, to two significant figures, of the fundamental charge that is suggested by these values of charge on oil drops.
\(3.2 \times 10^{-19} \mathrm{C}\)
Question 7
Question 7(a)
Describe the two main results of the \(\alpha\)-particle scattering experiment. result 1 : result 2:
the majority/most went straight through or were deviated by small angles B1 a very small proportion/a few were deviated by large angles B1 small angles described as \(<10^{\circ}\) and large angles described as \(>90^{\circ}\) B1 [3]
Question 7(b)
Relate each of the results in (a) with the conclusions that were made about the nature of atoms. result 1: result 2:
most of the atom is empty space/nucleus very small compared with atom B1 mass and charge concentrated in (very small) nucleus B1 correct links made with statements in (a) B1 [3]
Question 7
One of the isotopes of uranium is uranium-238 \(\left({ }_{92}^{238} \mathrm{U}\right)\).
Question 7(a)
State what is meant by isotopes.
nuclei/atoms with same proton number/atomic number B1 [2] nuclei/atoms contain different numbers of neutrons/different atomic mass B1
Question 7(b)
For a nucleus of uranium-238, state
Question 7(b)(i)
the number of protons, number =
92 A1 [1]
Question 7(b)(ii)
the number of neutrons. number =
146 A1 [1]
Question 7(c)
A uranium-238 nucleus has a radius of \(8.9 \times 10^{-15} \mathrm{~m}\). Calculate, for a uranium-238 nucleus,
Question 7(c)(i)
its mass, mass = kg
mass \(=238 \times 1.66 \times 10^{-27\) (c) (i) \(=3.95 \times 10^{-25} \mathrm{~kg}\) mass \(=238 \times 1.66 \times 10^{-27}\) (c) (i) \(=3.95 \times 10^{-25} \mathrm{~kg}\)} C1 [2]
Question 7(d)
The density of a lump of uranium is \(1.9 \times 10^{4} \mathrm{~kg} \mathrm{~m}^{-3}\). Using your answer to (c)(ii), suggest what can be inferred about the structure of the atom.
Question 7
Nuclei of an isotope of copper ( Cu ) each have 29 protons and 37 neutrons. This isotope is a \(\beta^{-}\)emitter.
Question 7(a)
State the nuclide notation in the form \({ }_{Z}^{A} \mathrm{X}\) for this nucleus of copper.
\({ }_{29}^{66} \mathrm{Cu}\) B1
Question 7(b)
The energy spectrum of the \(\beta^{-}\)radiation emitted by a sample of this isotope is shown in Fig. 7.1.
Question 7(b)(i)
Use Fig. 7.1 to explain why other particles apart from the \(\beta^{-}\)particles must be emitted during this decay.
the energy of the decay is fixed / constant B1 the energies of the beta particles have a (continuous) range of values / varies / not constant B1 another particle / an (anti)neutrino must possess the extra / remaining energy (difference between energy of the decay and the \(\beta\) kinetic energy) B1
Question 7(b)(ii)
State the name of the other particle emitted during the decay of this isotope.
(electron) antineutrino B1
Question 7(b)(iii)
The copper isotope decays to an isotope of zinc (Zn). Give the radioactive decay equation for this decay. Include the nucleon and proton numbers of all the particles involved.
\[ { }_{29}^{66} \mathrm{Cu} \rightarrow{ }_{30}^{66} \mathrm{Zn}+{ }_{-1}^{0} \beta+{ }_{0}^{0} \overline{\mathrm{v}_{\mathrm{e}}} \] values for Cu and Zn correct with no other extra particles on either side of the equation B1 second term correct ( \({ }_{-1}^{0} \beta\) ) B1 third term correct ( \({ }_{0}^{0} \overline{\mathrm{v}_{\mathrm{e}}}\) ) B1