2: Particles and Radiation Flashcards
What are isotopes?
Atoms with the same number of protons but a different number of neutrons.
What are the three constituents of an atom?
Protons, Neutrons, Electrons.
What is the mass of protons and neutrons?
1.67x10^-27
What is the mass of an electron?
9.11x10^-31
How do you calculate specific charge?
Charge / mass
what does ‘specific’ mean?
Per unit mass e.g. per Kg
what is specific charge?
Charge per unit mass or charge mass ratio
How do you work out the specific charge of a proton/individual particle?
Charge / mass
1.60 x10^-19 / 1.67 x10^-27 = 9.58 x10^7 Ckg^-1
How do you work out specific charge of a nucleus?
Example: Calcium
charge / mass
20 x 1.60x10^-19 / 40 x 1.67x10^-27 = 4.79x10^7 CKg^-1
How do you work out the specific charge of an ion?
Example: Aluminium
charge / mass
3 x 1.60x10^-19 / 27 x 1.67x10^-27 + 10 x 9.11x10^-31 = 1.06x10^7
Where does strong nuclear force happen?
Between Nucleons (particles in a nucleus)
When do strong nuclear forces repell?
between 0 and 0.5 Femtometres
Where do strong nuclear forces attract?
Between 0.5 and 3 femtometres
Where is there no strong nuclear force?
Beyond 3 femtometres
What does it mean by a ‘stable nucleus’?
When both strong nuclear forced and electromagnetic forces are balanced.
How do we work out alpha radiation?
-4 neutrons, -2 protons
How do we work out beta radiation?
-1 proton
What happens during gamma radiation?
The Nucleus loses energy.
What is an anti-electron neutrino?
In nuclear decay, only a discreet amount of energy can be released. There must be another particle carrying energy. Anti-electron neutrinos are really hard to detect yet hold this energy. (only applicable in Beta radiation)
How do you go from Volts to ElectronVolts?
Times the electrons by the volts.
What is an electronvolt?
One electronvolt is the kinetic energy gained when a charge of 1e is accelerated by a potential difference of 1V.
How do you convert between electronvolts and joules?
ev –> J = x 1.60x10^-19
J –> ev = / 1.60x10^-19
What is rest energy?
Energy released when a particle’s rest mass is converted into energy.
