Particles Flashcards
What is the force which overcomes the repulsive force within the nucleus ?
The strong nuclear force
What types of particles does the strong nuclear force impact ?
Hadrons ( neutrons and protons )
What is the purpose of the strong nuclear force ?
To overcome the repulsive electrostatic forces holding the nucleus together
At what distances is the strong nuclear force repulsive ?
Under 0.5 fm
What is the range of the strong nuclear force ?
3-4 fm (10^-15)
Why is the strong nuclear force repulsive at certain distances ?
To prevent the protons and neutrons from colliding into each other
Why does alpha decay occur ?
The atom is too large for the strong nuclear force to keep stable
What is an alpha particle ?
A helium nucleus consisting the nucleon number 4 and proton number 2
What happens to the nucleon number as the particle undergoes alpha decay ?
Decreases by 4
What happens to the proton number as the particle undergoes alpha decay ?
Decreases by 2
What is the range of an alpha particle ?
A few centimetres (short range )
Why does beta minus occur ?
Due to the high ratio of neutrons to protons , converting a neutron to a proton
What is ionisation ?
The removal or addition of electrons from an atom or molecule
Which beta decay converts a neutron to a proton ?
Beta minus decay
What does a beta minus decay emit ?
A beta particle along with an antineutrino
What happens to the the nucleon number during the emission of a beta particle ?
The nucleon number remains the same
What happens to the proton number as a beta minus particle is emitted ?
The proton number increases by one
Explain why alpha dust is hazardous to an unprotected human
- can enter the body through ingesting or breathing in the particles which can kill cells as the human cells and tissues become damaged
How had neutrinos been discovered ?
- the energy after the decay had been lower than the initial energy (not following the conservation of energy principle )
This lead to the suggestion that another particle is also emitted with almost no mass and charge
What is a gamma radiation ?
An electromagnetic radiation emitted by an unstable nucleus
Why is gamma radiated ?
Particles with too much energy following an alpha or a beta emission
What does every particle have ?
An antiparticle with the same mass and rest energy but an apposite charge
Why does annihilation occur ?
When a particle comes into contact with its antiparticle
What occurs when a particle is annihilated?
The mass is converted into energy producing two photons in opposite directions