Chapter 9- Nuclear Decay Flashcards
Who discovered radioactivity
Marie curie
What is background radiation
Radiation that is constantly present in our environment
Dangers of radiation caused by (2)
Exposure of bodies to external sources
Breathing/ingesting radioactive matter
Radiation has a chance of causing
Cancer
Which material to store radioactive materials
Lead storage containers
Sources of background radiation
1) gamma rays emitted from ground and buildings
2) medical -sterilisation etc radiotherapy
3) food and drink
4) radon gas from the ground
5) nuclear waste
6) cosmic rays
What is a cosmic ray
A high energy ray that bombards earths atmosphere producing showers of lower energy particles such as neutrons or electrons
Roughly how much radiation percentage is exposed due to natural sources
85%
Radiation percentage due to artificial sources
15%
What is ionisation
When the electrons are given sufficient energy to break free from their atoms
Alpha radiation can be detected using either (2)
- spark counter
- ionisation chamber
What type can be absorbed by a thin sheet of paper
Alpha
Which types can be deflected by a strong magnetic and electric field
Alpha
Beta
Positively charged particles
Alpha
Alpha particles are actually…
Helium nuclei
Helium nuclei made from
2 protons and 2 neutrons
Why doesn’t alpha particle pass through matter
Particle is easily absorbed as it passes through
They readily ionise
So energy is rapidly lost and the particle is quickly brought to rest
What can detect beta radiation
Geiger müller tube
GM tube
What is beta radiation
Electron
Fast moving streams of negatively charged electrons
A beta has ______ the mass of an alpha
1/8000th
Why are beta particles not absorbed my paper
Because they can penetrate matter much further before their energy is used up
Games radiation is a form of
High energy form of electromagnetic radiation
Gamma radiation is made up of
Minute discrete bundles of energy called photons
Charge of alpha
+ 2e
Charge of beta
-e
Charge of gamma
0
Mass of gamma
0
Mass of beta
9.11x10^-31
1/8000th of alpha
Mass of alpha
6.64x10^-27 kg
Speed of gamma
C= 3x10^8
Speed of beta
0.99 x c
Speed of alpha
Up to 1/20 c
Which type has greatest energy
Alpha
Which type has greatest relative ionising power
Alpha
Alpha can penetrate
Few cm of air
Beta can penetrate
Few mm of aluminium
Gamma can penetrate
Few cm of lead
Alpha deflection in electric and magnetic fields
Small deflection
Beta deflection in magnetic and electric fields
Large deflection
They have v small mass
Gamma deflection in magnetic and electric fields
No deflection
As they have no charge
Alpha particle nature
Helium nucleus
Beta particle nature
Electron
Gamma photon nature
High frequency electromagnetic radiation
Ionising radiation comes from
The unstable nuclei of radioactive elements
Which on emission of an alpha particle or a beta particle, decay into another lower energy nuclei
Proton number
Number of protons in nuclei
Proton number the same as the number of
Electrons
Atomic Number is
The proton number
Nucleon number
Number of neutrons in nucleus
Neutron number is also called
The mass number
Mass number when seen on periodic table
The massive number on top
What is an isotope
Same number of protons
Diff number of neutrons
Same element
How to determine percentage abundance
Do percentages of each type in 0-1 form and use the numbers given
