CAIE A-Level Physics AS 11 Particle Physics Questions

Practise analysing atomic and nuclear structure, scattering, isotopes, radiation, decay equations, quark composition, leptons and nuclear mass units.

Exam points

interpret alpha-scattering evidence and nuclear-atom structure
determine nuclide composition, isotopes, notation, charge and conserved quantities
analyse alpha and beta radiation, antiparticles, neutrinos, energy spectra and decay equations
use quark composition and charge to classify hadrons and explain beta decay
distinguish fundamental leptons from composite particles and use u for nuclear mass

Covered syllabus points

11.1 Atoms, nuclei and radiation 11.2 Fundamental particles

[Maximum number: 1]

Which statement about the alpha-particle scattering experiment provides evidence for the existence of the nucleus?

A tiny proportion of the alpha-particles are deflected through large angles.

Slower alpha-particles are deflected through larger angles.

The kinetic energies of the deflected alpha-particles are unchanged.

The number of alpha-particles deflected depends on the thickness of the foil.

[Maximum number: 6]

(a)

State the name of the class (group) of fundamental particles that contains a neutrino.

[ 1 ]

(b)

A hadron P has a charge of +1 e, where e is the elementary charge. The hadron P is composed of a down antiquark and only one other quark.

[ 2 ]

(i)

Identify a possible flavour for this other quark.

[ 1 ]

(ii)

State what type of hadron is P .

[ 1 ]

(c)

Nucleus Q undergoes radioactive decay to form nucleus R, emitting an antineutrino and another particle X, as shown in the decay equation.

Q \rightarrow R+X+\bar{v}

[ 3 ]

(i)

State what particle is represented by X .

[ 1 ]

$\beta^{-}$ (particle) or electron

(ii)

Compare the nucleon numbers of Q and R.

[ 1 ]

(iii)

Compare the charges of Q and R.

[ 1 ]

[Maximum number: 7]

(a)

Describe the structure of an atom of uranium-238, $\stackrel{238}{92} \mathrm{U}$ .

[ 2 ]

(b)

The decay of uranium-238 is shown by the equation

{ }_{92}^{238} \mathrm{U} \rightarrow{ }_{90}^{234} \mathrm{Th}+\mathrm{X} .

For nucleus X , calculate the ratio, in $\mathrm{Ckg}^{-1}$ , of $\frac{\text { charge }}{\text { mass }}$ .
ratio = $\mathrm{C} \mathrm{kg}^{-1}$

[ 3 ]

charge =2 e
$\left(=2 \times 1.60 \times 10^{-19} \mathrm{C}\right)$
mass =4 u
$\left(=4 \times 1.66 \times 10^{-27} \mathrm{~kg}\right)$
ratio $=\left(2 \times 1.60 \times 10^{-19}\right) /\left(4 \times 1.66 \times 10^{-27}\right)$ $=4.8 \times 10^{7} \mathrm{C} \mathrm{~kg}^{-1}$

(c)

Two particles P and Q each consist of three quarks. These quarks are up (u) or down (d) quarks.

Particle P has no overall charge.
Particle Q has an overall charge of +2 e, where e is the elementary charge.
State the quark composition of:

[ 2 ]

(i)

particle P

[ 1 ]

(ii)

particle Q.

[ 1 ]

[Maximum number: 1]

The diagrams show the quark composition of four different hadrons. One of the hadrons is a $\Sigma^{+}$ particle. It has a charge of +e, where e is the elementary charge.

Which hadron could be the $\Sigma^{+}$ particle?

Figure for Question 4 — CAIE A-Level Physics AS — Option A

Figure for Question 4 — CAIE A-Level Physics AS — Option B

Figure for Question 4 — CAIE A-Level Physics AS — Option C

Figure for Question 4 — CAIE A-Level Physics AS — Option D

key
u = up quark
d= down quark
s= strange quark

All question bank results loaded

Covered syllabus points

Question 1

Question 2

Question (a)

Question (b)

Question (i)

Question (ii)

Question (c)

Question (i)

Question (ii)

Question (iii)

Question 3

Question (a)

Question (b)

Question (c)

Question (i)

Question (ii)

Question 4