P2 Radioactivity Flashcards
What is radioactive decay?
Unstable nuclei decaying to become more stable.
Which two words best describe radioactive decay?
Random and spontaneous
What was important about Rutherford’s scattering experiment?
It demonstrated the existence of the tiny positive nucleus
What is background radiation?
Radiation that is all around us - major sources are from rocks (granite) and medical uses and (very small) nuclear accidents
What is an alpha particle?
A helium nucleus - 2 protons and 2 neutrons It has a +2 charge It has a mass of 4
What is a beta particle?
An electron from the nucleus It has a charge of -1 It has a mass of 1 / 2000
What is gamma radiation?
An electromagnetic wave It has no charge It has no mass
What is half life?
Half life is the time taken for half of the nuclei in a sample to decay
What are the 3 types of nuclear radiation?
alpha beta gamma
What happens to the mass number and atomic number of a nucleus that emits an alpha particle?
Mass number decreases by 4
Atomic number decreases by 2
Fill in the blanks for this alpha decay:
92U238 ——> ___Th___ + ___ alpha____
92U238 ——> 90Th234 + 2alpha4
Fill in the blanks for this beta decay:
6C14 ——> __N__ + ___beta___
6C14 ——> 7N14 + -1beta0
Put alpha, beta and gamma in ordering of their penetrating power
Most penetrating: gamma
beta
Least penetrating: alpha
Put alpha beta and gamma in order of their ionising power
Most ionising: alpha
beta
Least ionising: gamma
Which type(s) of radiation are affected by electric and magnetic fields?
Alpha and beta
but not gamma.
This is because alpha and beta carry charge
