The Standard Model

Question 1

What is a fundamental particle?

Answer 1

A fundamental particle has no internal structure and is not made of anything smaller

Question 2

There are six electron like particles called?

Answer 2

Leptons, three are negatively charged and each of these has an associated neutral charged particle, it’s neutrino

Generation 1 - the electron and it’s electron neutrino

Generation 2 - the muon and it’s muon neutrino

Generation 3 - the Tauon and it’s tauon neutrino

Question 3

Which of the following statements about the Standard Model of fundamental particles is/are correct?
i The matter giving particles are called quarks and leptons.
ii The force mediating particles are called bosons.
iii Fermions are fundamental particles.
a) (ii) only
b) (i) and (ii) only
c) (i) and (iii) only
d) (ii) and (iii) only
e) (i), (ii) and (iii)

Answer 3

b) (i) and (ii) only

Question 4

Which of the following statements about the Standard Model of fundamental particles is/are correct?
i There are two groups of matter particles, called quarks and leptons.
ii There are two different types of hadrons, called baryons and mesons.
iii The electron is a member of the lepton group.
a) (ii) only
b) (i) and (ii) only
c) (i) and (iii) only
d) (ii) and (iii) only
e) (i), (ii) and (iii)

Answer 4

e) (i), (ii) and (iii)

Question 5

Which of the following statements about protons and neutrons is/are correct?
i Protons and neutrons are two of many types of hadron.
ii Protons and neutrons are baryons with baryon number 1.
iii Protons and neutrons within a nucleus are unstable.
a) (i) only
b) (i) and (ii) only
c) (ii) and (iii) only
d) (i) and (iii) only
e) (i), (ii) and (iii)

Answer 5

b) (i) and (ii) only

Question 6

Which of the following statements about the stability of the particles in the Standard Model of fundamental particles is/are correct?
i All hadrons are thought to be stable and do not decay.
ii Free neutrons are unstable, with a half-life of approximately fifteen minutes, and decay to produce a proton and a beta particle.
iii Free protons are unstable and it is thought that they have a half-life of the order of 1032 years.
a) (iii) only
b) (i) and (ii) only
c) (i) and (iii) only
d) (ii) and (iii) only
e) (i), (ii) and (iii)

Answer 6

d) (ii) and (iii) only

Question 7

Which of the following statements about conservation and interactions involving particles in the Standard Model of fundamental particles is/are correct?
i The electrical charge of a hadron is conserved during a nuclear reaction.
ii Baryon number is conserved during an interaction.
iii Strangeness number is conserved in interactions involving hadrons.
a) (i) only
b) (i) and (ii) only
c) (i) and (iii) only
d) (ii) and (iii) only
e) (i), (ii) and (iii)

Answer 7

e) (i), (ii) and (iii)

Question 8

Which of the following statements about the strong force is true?

a) The strong force and the gravitational force between two protons in a nucleus are roughly equal in magnitude.
b) The strong force can act between two protons or two neutrons, but not between a proton and a neutron.
c) The strong force can act on protons, neutrons and electrons.
d) The strong force is a short-range force. e) The strong force can act over any distance.

Answer 8

d) The strong force is a short-range force

Question 9

Which of the following contains only flavours of quark?

a) up; down; top; bottom; left; right
b) top; bottom; glue; colour; left; right
c) up; down; strange; charm; top; bottom
d) strange; charm; glue; colour; left; right
e) strange; charm; up; down; glue; colour

Answer 9

c) up; down; strange; charm; top; bottom

Question 10

Which of the following statements about the simple quark model of hadrons is/are correct?
i All mesons are composed of three quarks or three antiquarks.
ii Baryons are composed of a quark and an antiquark.
iii The properties of all hadrons can be described in terms of the simple quark model.
a) (iii) only
b) (i) and (ii) only
c) (i) and (iii) only
d) (ii) and (iii) only
e) (i), (ii) and (iii

Answer 10

a) (iii) only

Question 11

A hydrogen atom consists of one proton, one electron and no neutrons. How many quarks are there in a hydrogen atom?

a) 0
b) 1
c) 2
d) 3
e) 4

Answer 11

d) 3

Question 12

Which force is associated with β-decay?

a) strong force
b) weak force
c) gravitational force
d) electromagnetic force
e) depends on the atom in which the decay takes place

Answer 12

b) weak force

Question 13

Select the correct words within the brackets for the following paragraphs concerning fundamental particles.
Fundamental particles are particles which are thought to have no underlying structure. The {electron/proton/antiproton} is an example of a fundamental particle. It belongs to a group of particles called the {leptons/kaons/bosons}.
Particles such as {neutrinos/neutrons/positrons} are not fundamental particles. These particles are members of a group known as the hadrons. The hadrons are divided into two sub-groups called the baryons and the {fermions/kaons/mesons}.
All hadrons comprise combinations of fundamental particles called quarks. The baryons are made up of {two/three/four} quarks. There are six main types of quark. One type is called the up quark, another type is the {top/middle/lower} quark

Answer 13

Electron
Leptons 
Neutrons
Mesons
Three
Top

Question 14

In the radioactive decay of a hadron particle, a quark, QA, with +2/3 units of charge is transformed to a quark, QB, with charge -1/3 units. In this decay process, a charged particle, Cp, is released. The following statement represents this decay. The charge on each of the quarks is shown below the statement. QA → QB + Cp +2/3 −1/3

a) How many units of charge will be removed from the particle as a result of the decay process? A) +2/3 
B) +1 
C) -1 
D) +2 
E) -1/3 

b) Which of the following particles is emitted in the decay process?
A) Up quark 
B) Positron 
C) Alpha particle 
D) Down quark 
E) Electron

c) Which of the following interactions is involved in the decay process?
A) Strong 
B) Weak 
C) Gravitational 
D) Electromagnetic 
E) Electrostatic

Answer 14

a) B
b) B
c) B

Question 15

The up quark has +2/3 units of charge. The down quark has -1/3 units of charge. An up quark is represented by the symbol u and a down quark by the symbol d. The antiquarks of the u and d quarks have symbols u and d respectively.

a) Which of the following combinations of quarks could constitute an antiproton?
A) u u d 
B) u d d 
C) u d d 
D) u dd 
E) u u d 

b) The π- particle carries a charge of -1 units and is a member of the meson family. Which of the following combinations of quarks could constitute a π- particle? 
A) d u 
B) d u 
C) u d 
D) d u u 
E) d d u

Answer 15

a) A

b) A

Question 16

How many protons are needed to carry a charge of 1 C?

a) 1.6 x 10-19
b) 8.85 x 10-12
c) 1
d) 6.25 x 1018
e) 1.6 x 101

Answer 16

d) 6.25 x 1018

Question 17

Two metal spheres are hangingfrom nylon threads. When the spheres are brought close together they repel each other. Which one of the following statements could be true?

a) One sphere is negatively charged, the other is positively charged.
b) One sphere is uncharged, the other is positively charged.
c) One sphere is uncharged, the other is negatively charged.
d) Both spheres are uncharged.
e) Both spheres are positively charged.

Answer 17

e) Both spheres are positively charged.

Question 18

When a positive charge is placed in an electric field it

a) experiences a force.
b) loses its charge.
c) moves in a circle.
d) becomes a negative charge. e) doubles its charge

Answer 18

a) experiences a force.