Radio Active Decay Flashcards
4 types of nuclear radiation?
α, β(-), β(+),ɣ
Properties of α?
Strong ionisation
weak penetration (paper/ air)
made of 2 protons and 2 neutrons
slow
caused by decay of heavy nuclei
Properties of β?
Weaker ionisation
Stronger penetration ( thin aluminium) or (no range for positron one)
electrons/positron
fast
caused by neutron-rich nuclei
Properties of ɣ?
Weak ionistaion
Strong penetration (lead or concrete)
photons
light speed
caused by nuclei with too much energy
What must be done to readings from a Geiger counter?
Subtract the background radiation
What must be conserved in calculations?
The Charge and the mass number must be conserved
What is activity?
The number of nuclei that decay each second
A = decay constant * number of undecayed nuclei
A = λN
What is the decay equation?
N = N(0)e^(-λt)
N(number of undecayed nuclei) can be substituted for A(activity)
The formula relating half-life and decay constant
λ = ln2 / t(1/2)
What is the mass deficit?
The difference between the starting mass and end mass when nucleons combine in fusion, caused by the exchange of mass to energy via E = mc^2
What does both fission and fusion cause?
The binding energy per nucleon increases (look at the diagram u bum)
What happens if the binding energy per nucleon increases?
The particle is more stable
Requirements for fission
Shoot a neutron at a large unstable nuclei causing it to split
Requirements for fusion?
High temperatures and Density/ Pressure
What is meant by binding energy?
The energy equivalent to the mass deficit when nucleons bind together to form a nucleus
