Particles and radiation Flashcards
Isotopes
Same proton number but different nucleon number
Atomic structure
Protons and neutrons in nucleus
Electrons in orbit
Charge of Proton
1.6 x 10^-19
Charge of neutron
0
Charge of electron
-1.6 x 10^-19
Mass of proton
1.673 x 10^-27
Mass of neutron
1.675 x 10^-27
Mass of electron
9.11 x 10^-31
Relative charge of Proton, Neutron and Electron
+1 , 0 , -1
Relative mass of Proton, Neutron and Electron
1, 1, 0.0005
Specific charge
Charge/mass = Ckg^-1
Use of strong nuclear force?
Glues the nucleus together
Stronger than electrostatic force (repulsion)
What is alpha decay?
Parent nucleus turns from one nucleus to a daughter nucleus and emits an alpha particle (Helium 4)
Rest energy is conserved
What is beta decay?
A neutron turns into a proton and electron emitted
Releases another nucleus with new atom and higher proton number
Process is meant to conserve energy but beta particles which are emitted have less KE ==> Energy not conserved
Neutrinos is the third particle missing
What are anti-particles?
Every particle has a corresponding antiparticle with the same mass but opposite charge
Anti particle of an electron?
Positron
Antiparticle of a proton?
Antiproton
Antiparticle of a neutron and neutrino
Antineutron and antineutrino
What is rest energy?
The energy a particle with any amount of mass has even while stationary
Measured in MeV
Antiparticle has the same rest energy as their corresponding particle
What is a photon?
A quantum of EM radiation
Quanta (discrete packets of energy)
No mass
How to calculate energy of a photon?
E = hf
E = energy carried (Joules)
h = Planck’s constant
f = frequency
What is Planck’s constant?
6.63 x 10^-34
Wave speed in this case?
C = f x wavelength
f = c/wavelength
E=hf or
E=h c/wavlength
Annihilation
Conversion of a particle and antiparticle into a pair of gamma ray photons where the rest energy of the particle and antiparticle is converted into the energy of the photons
Photons travel in opposite directions