Define antimatter particle .

An antimatter particle is identical to its matter counterpart but has the opposite charge .

Which particles are their own antiparticle?

Neutral particles, such as the neutron and the neutrino .

How is an antiparticle's symbol usually shown, and what is the exception?

Antiparticles use the same name and symbol as the matter particle with the prefix 'anti-' and a line above the symbol . The exception is the electron , whose antiparticle is called the positron .

Antimatter particles have identical mass and rest mass-energy to their matter counterparts, but .......... charge.

Antimatter particles have identical mass and rest mass-energy to their matter counterparts, but opposite charge.

Define rest mass-energy .

The rest mass-energy of a particle is the energy equivalent to the mass of the particle at rest.

True or False? An antiproton has a different mass to a proton.

False. An antiproton has identical mass and rest mass-energy to a proton; only its charge is opposite.

A hadron is a particle made up of quarks , and so is affected by the strong nuclear force .

What are the two classes of hadron, and how many quarks does each contain?

Baryons (three quarks) and mesons (a quark and an antiquark pair).

Give an example of a common baryon and a common meson.

Common baryons : protons and neutrons. Common mesons : pions and kaons.

A lepton is a fundamental particle that is not made up of quarks, and so is not affected by the strong nuclear force .

Muon and tau particles are similar to electrons but with slightly .......... masses.

Muon and tau particles are similar to electrons but with slightly larger masses.

True or False? Leptons interact via the strong nuclear force.

False. Leptons do not interact via the strong force; they interact via the weak interaction , the electromagnetic force and gravity .

Name the three charged flavours of lepton.

The electron , the muon and the tau . Each also has a corresponding neutrino (electron neutrino, muon neutrino, tau neutrino), which is uncharged.

A baryon is a hadron made up of three quarks .

A meson is a hadron made up of a quark and an antiquark pair .

What is true of the quark composition of a baryon?

The quarks in a baryon are either all quarks or all antiquarks — a mix of quarks and antiquarks never occurs, since all baryons have integer charge .

A proton is made up of two .......... quarks and one down quark.

A proton is made up of two up quarks and one down quark.

What is the quark composition of a neutron?

Two down quarks and one up quark (udd).

Define the charge of a hadron , in terms of its quarks.

The charge of a hadron is equal to the sum of the charges of its constituent quarks.

What are the relative charges of an up quark and a down quark?

Up quark: +⅔*e . Down quark: −⅓ e *.

True or False? An anti-down quark has a charge of −⅓ e .

False. Antiquarks have the opposite charge to their corresponding quark, so an anti-down quark has a charge of +⅓*e *.

Define beta-minus (β⁻) decay .

Beta-minus decay is when a neutron turns into a proton , emitting an electron and an anti-electron neutrino .

Define beta-plus (β⁺) decay .

Beta-plus decay is when a proton turns into a neutron , emitting a positron and an electron neutrino .

What happens to the proton number and nucleon number of a nucleus during β⁻ decay?

The proton number increases by one ; the nucleon number stays the same .

In β⁺ decay, the proton number .......... by one, while the nucleon number stays the same.

In β⁺ decay, the proton number decreases by one, while the nucleon number stays the same.

Which quark transformation underlies β⁻ decay?

A down quark turns into an up quark .

Which quark transformation underlies β⁺ decay?

An up quark turns into a down quark .

True or False? Beta decay happens via the strong nuclear force.

False. Beta decay happens via the weak interaction , one of the four fundamental forces.

Which particles are emitted during the beta-minus quark transformation d → u?

An electron (e⁻) and an electron antineutrino .

Which particles are emitted during the beta-plus quark transformation u → d?

A positron (e⁺) and an electron neutrino .

In beta-minus decay, a .......... quark converts into an up quark, emitting an electron and an antineutrino.

In beta-minus decay, a down quark converts into an up quark, emitting an electron and an antineutrino.

Define what it means for charge to be conserved in a decay equation.

The total charge on the left-hand side of the equation must equal the total charge on the right-hand side.

True or False? Charge only needs to balance in beta-minus decay equations, not beta-plus decay equations.

False. Charge must be conserved in every reaction or decay equation , including both beta-minus and beta-plus decay.

A LevelPhysicsOCRFlashcards6. Particles & Medical PhysicsFundamental Particles

Fundamental Particles (OCR A Level Physics): Flashcards

Exam code: H556

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Define antimatter particle.

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Cards in this collection (36)

Define antimatter particle.
An antimatter particle is identical to its matter counterpart but has the opposite charge.
Which particles are their own antiparticle?
Neutral particles, such as the neutron and the neutrino.
How is an antiparticle's symbol usually shown, and what is the exception?
Antiparticles use the same name and symbol as the matter particle with the prefix 'anti-' and a line above the symbol. The exception is the electron, whose antiparticle is called the positron.
Antimatter particles have identical mass and rest mass-energy to their matter counterparts, but .......... charge.
Antimatter particles have identical mass and rest mass-energy to their matter counterparts, but opposite charge.
Define rest mass-energy.
The rest mass-energy of a particle is the energy equivalent to the mass of the particle at rest.
True or False?
An antiproton has a different mass to a proton.
False.
An antiproton has identical mass and rest mass-energy to a proton; only its charge is opposite.
What is the antimatter particle of the electron called?
The positron.
Define hadron.
A hadron is a particle made up of quarks, and so is affected by the strong nuclear force.
What are the two classes of hadron, and how many quarks does each contain?
Baryons (three quarks) and mesons (a quark and an antiquark pair).
Give an example of a common baryon and a common meson.
Common baryons: protons and neutrons. Common mesons: pions and kaons.
Define lepton.
A lepton is a fundamental particle that is not made up of quarks, and so is not affected by the strong nuclear force.
Muon and tau particles are similar to electrons but with slightly .......... masses.
Muon and tau particles are similar to electrons but with slightly larger masses.
True or False?
Leptons interact via the strong nuclear force.
False.
Leptons do not interact via the strong force; they interact via the weak interaction, the electromagnetic force and gravity.
Name the three charged flavours of lepton.
The electron, the muon and the tau. Each also has a corresponding neutrino (electron neutrino, muon neutrino, tau neutrino), which is uncharged.
Define baryon.
A baryon is a hadron made up of three quarks.
Define meson.
A meson is a hadron made up of a quark and an antiquark pair.
What is true of the quark composition of a baryon?
The quarks in a baryon are either all quarks or all antiquarks — a mix of quarks and antiquarks never occurs, since all baryons have integer charge.
A proton is made up of two .......... quarks and one down quark.
A proton is made up of two up quarks and one down quark.
What is the quark composition of a neutron?
Two down quarks and one up quark (udd).
Define the charge of a hadron, in terms of its quarks.
The charge of a hadron is equal to the sum of the charges of its constituent quarks.
What are the relative charges of an up quark and a down quark?
Up quark: +⅔*e. Down quark: −⅓e*.
True or False?
An anti-down quark has a charge of −⅓e.
False.
Antiquarks have the opposite charge to their corresponding quark, so an anti-down quark has a charge of +⅓*e*.
Define beta-minus (β⁻) decay.
Beta-minus decay is when a neutron turns into a proton, emitting an electron and an anti-electron neutrino.
Define beta-plus (β⁺) decay.
Beta-plus decay is when a proton turns into a neutron, emitting a positron and an electron neutrino.
What happens to the proton number and nucleon number of a nucleus during β⁻ decay?
The proton number increases by one; the nucleon number stays the same.
In β⁺ decay, the proton number .......... by one, while the nucleon number stays the same.
In β⁺ decay, the proton number decreases by one, while the nucleon number stays the same.
Which quark transformation underlies β⁻ decay?
A down quark turns into an up quark.
Which quark transformation underlies β⁺ decay?
An up quark turns into a down quark.
True or False?
Beta decay happens via the strong nuclear force.
False.
Beta decay happens via the weak interaction, one of the four fundamental forces.
Which particles are emitted during the beta-minus quark transformation d → u?
An electron (e⁻) and an electron antineutrino.
Which particles are emitted during the beta-plus quark transformation u → d?
A positron (e⁺) and an electron neutrino.
In beta-minus decay, a .......... quark converts into an up quark, emitting an electron and an antineutrino.
In beta-minus decay, a down quark converts into an up quark, emitting an electron and an antineutrino.
Define what it means for charge to be conserved in a decay equation.
The total charge on the left-hand side of the equation must equal the total charge on the right-hand side.
Show that charge is conserved in the beta-minus quark equation d → u + e⁻ + antineutrino.
LHS charge: −⅓*e*.
RHS charge: $+ \frac{2}{3} e + (- 1) e + 0 = - \frac{1}{3} e$ .
LHS = RHS, so charge is conserved.
Show that charge is conserved in the beta-plus quark equation u → d + e⁺ + neutrino.
LHS charge: +⅔*e*.
RHS charge: $- \frac{1}{3} e + (+ 1) e + 0 = + \frac{2}{3} e$ .
LHS = RHS, so charge is conserved.
True or False?
Charge only needs to balance in beta-minus decay equations, not beta-plus decay equations.
False.
Charge must be conserved in every reaction or decay equation, including both beta-minus and beta-plus decay.

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