Particle and Quantum Flashcards
State the deduction of the a-particle scattering experiment
- Most α-particles passed straight through: the atom is mostly empty space.
- Some deflected at small angles (<10°) : indicating a positive nucleus repelling positive charges.
- A small number deflected back (>90°): showing the nucleus is tiny, dense, and holds the atom’s mass and positive charge.
Conclusion: Atoms have small, dense, positively charged nuclei surrounded by negative electrons.
State the relative charge and mass of: proton, electron and the neutron
Relative charge :
Proton: +1
Electron: -1
Neutron : 0
Relative mass:
Proton: 1
Electron: 1/2000
Neutron: 1
State the value of the unified atomic mass unit. And what it is equal to
1 u = 1.66 × 10−27 kg
It is roughly = mass of proton or neutron
Define the following:
Nuclide
Nucleon no.
Isotope no.
Nuclide: a nucleus with a specific combination of protons and neutrons
Nucleon number: no. of protons + no. of neutrons
An isotope: an atom (of the same element) that has an equal number of protons but different number of neutrons.
discuss the stability of isotopes
Isotopes with imbalanced neutrons and protons are unstable and decay by emitting radiation to become stable.
Explain the Conservation of nuclear charge
Fission and fusion are represented using nuclear equations
In nuclear equations,the nucleon number and charge are always conserved.
This means that the sum of the nucleons and charge on the left hand side must equal the sum of the number of nucleons and charge on the right hand side.
What are the nuclear proccesses?
Fission and Fussion
State the radioactive emissions and their composition, mass and charge
alpha: 2p+2n
mass: 4u
beta negative: e
mass: 1/2000u
beta positive: e+
mass: 1/2000u
gamma: electromagnetic wave
mass: 0u
ionisations and penetrations
describe the three emissions
alpha :
Most ionizing: Has a great charge
Least penetrating: Too large
beta:
Has a charge so can ionise but not as much as alpha.
Penetrates but not as much as gamma.
gamma:
Least ionizing: Has no charge
Most penetrating: Very small
What is a neutrino?
An electron neutrino is a type of subatomic particle with no charge and negligible mass which is also emitted from the nucleus
When are neutrinos and antineutrinos emitted
Electron anti-neutrinos produced during β– decay
Electron neutrinos produced during β+ decay
Describe the energy difference bw/ alpha and beta emissions
Alpha particles: Have discrete energy levels (spikes on a graph), indicating fixed energies.
Beta particles: Show a continuous energy range (curve on a graph) as energy is shared with neutrinos. This distribution supported neutrino existence.
Conservation of momentum and energy applies to both alpha and beta emissions.
State the numerical changes in alpha decay with an example
₉₆²³²U → ₉₄²²⁸Th + ⁴₂a
What is an antimatter?
Antimatter particles are identical to their matter counterpart but with the opposite charge.
State the numerical changes in a B- decay
when a neutron turns into a proton emitting an electron and an anti-electron neutrino
no antoganists escape from prison
State the numerical changes in a B+ decay
a proton turns into a neutron emitting a positron (anti-electron) and an electron neutrino
what are the fundamental particles
fundamental particles that make up other subatomic particles such as protons and neutrons.
- Quarks
- Leptons
Describe how quarks are categorised
Hadrons: Particles made up of quarks
Hadrons are divided into Baryons and Mesons
Baryons have Protons and Neutrons
What are mesons and baryons and their antimatter?
Mesons : quark and anti-quark pair
Anti-Meson: anti-quark and quark pair
Baryons: 3 quarks
Anti-Baryons: 3 anti-quarks
What are the quarks and their charges? And anti-quarks and their charges
Up, Top, Charm: +2/3e
Down, Bottom, Strange: -1/3e
Anti- (Up, Top, Charm): -2/3e
Anti-(Down, Bottom, Strange): +1/3e
What are the quarks that make up a proton, neutron, anti-proton and an anti-neutron?
proton:uud
neutron: udd
anti-proton: u̅u̅d̅
anti-neutron: u̅d̅d̅
What are leptons with an example
Leptons are fundamental particles. Eg: Electron, Electron Neutrino
What happens in B- decay in terms of quarks
the β⁻ decay equation:
n → p + e⁻ + ν̅ₑ
udd → uud + e⁻ + ν̅ₑ
Where:
- n = neutron
- p = proton
- e⁻ = beta particle (electron)
- ν̅ₑ = antineutrino
What happens in the B+ decay
the β⁺ decay equation:
p → n + e⁺ + νₑ
uud → udd + e⁺ + νₑ
Where:
- p = proton
- n = neutron
- e⁺ = beta particle (positron)
- νₑ = neutrino
