Fundamental Particles (CIE A Level Physics)

Which of the following sentences about antimatter is incorrect ? 

Fundamental or elementary particles are particles that aren't made up of smaller particles.

 What is the most common type of fundamental particle in the universe ?

In a nucleus of Tritium, , how many ‘down’ quarks are there?

Which row in the table gives the correct quark combination for the particle?

	Particle	Category	Quark combination
A	neutron	baryon
B	neutron	meson
C	proton	baryon
D	positive pion	meson

What are the numbers of hadrons, baryons and mesons in an atom of  ? 

Quarks are thought to make up protons and neutrons.

 The 'up' quark has a charge of  ; a 'down' quark has a charge of  , where e is the elementary charge (+ 1.6 × 10^–19 C)

 How many up quarks and down quarks must a proton contain ?

A CERN detector shows a signal only in the hadronic calorimeter. No signal is observed in the tracker, electromagnetic calorimeter or muon chambers.

Which particle must be responsible for this signal?

Some particles are made up of a combination of three quarks.

Which particle would not give a particle a charge of either +1.6 × 10⁻¹⁹ C or zero?

The composition of four different hadrons are shown in the diagram below. One of the hadrons is a Σ ⁺  particle. It has a charge of +e, where is e is the elementary charge.

 Which hadron could be the Σ ⁺  particle ?

When high-speed hadrons collide in particle accelerators, a positive pion (π⁺) is an unstable particle produced. The π⁺ particle has a charge of +e.
What is the quark combination of the π⁺ particle?

A graph of nucleon number A against proton number Z is shown in the diagram below.

The graph shows a cross that represents a nucleus P.

 Nucleus P decays by emitting an α-particle to form a nucleus Q.

Nucleus Q then decays by emitting a β^– particle to form a nucleus R.

 The quark composition of one nucleon in Q is changed during the emission of the β^– particle.

 What is the corresponding change in quark composition from nucleus Q to nucleus R ?

The equation for β^– decay is

  Using your knowledge of antiparticles and the weak interaction, what is the equation for β⁺ decay?