Nuclear Physics Flashcards
What is a half life
The amount of time taken for half of a large sample nuclei to decay
What is activity
The rate at which nuclear decay occurs
What is a Geiger counter
A device capable of detecting radioactive particles therefore activity as well
Give me the half life equation
N=No(1dived by2) to the power n
What’ is N In the half life equation
Number of unstable nuclei which is current
What is No in the half life equation
Original activity
What is small letter n in the half life equation
The number of half lives
What is the number of half life equation
n=t dived by t half
What is t in the other half life equation
Time passed
What is t half in the number of half life equation
Time of a single half life
Give me a use of half life
Measuring age
What are the three types of decay
Alpha
Beta
Gamma
What can stop alpha particles
Our skin
What can be penetrated by Beta and what can not be penetrated by Beta
Skin
Aluminium
What can stop gamma radiation
Seven mm of lead
Several m of concrete
Why does ALPHA have high ionisation ability
It has a charge of +2
Why does beta particles have medium ionisation ability
Has a charge of -1
Why does gamma have low ionising ability
It has no mass or charge
Why is alpha particles easily stopped
Has a 2+ charge and is very heavy
Why is beta easily stopped by several mm of aluminium
Has a -1 charge and a small mass
Why is gamma easily stopped by several metres of concrete or several cm of lead
It has no charge and no mass
What is artificial transmutation
Nuclear decay which can be force upon a nuclide through human involvement
Define transmutation
Changing the nucleus
What is mass defect
the difference in mass between an atom and the sum of protons, neutrons and electrons in the atom
What is binding energy
the minimum energy required to disassemble a nucleus into its constituent particles (free protons and neutrons).
What is background radiation
Materials in a particular place and or the geology of a particular region
what is radioactive decay
the spontaneous breakdown of the nucleus of an atom resulting in the emission of particles or rays. There are three main types of decay.
what is alpha decay
occurs when an atom is unstable as it has too much mass
what do alpha particles consist of?
Alpha particles consist of two protons and two neutrons, like a helium nucleus
what is the SI unit of absorbed dose
The S.I. unit for absorbed dose is the GRAY
what is one GRAY equal to
1 Gy = 1 joule of energy absorbed per kilogram.
what is the formula of dose equivalent
dose equivalent
= absorbed dose x QF
what are the SI unit for DOSE EQUIVALENT
SIEVETS (Sv)
what is nuclear fission
the splitting of the nucleus of an atom to produce two relatively equal daughter products together with a large amount of energy
what is fusion
Fusion involves the joining of two light atomic nuclei to form one heavier nucleus
The higher the binding energy per nucleon in the nucleus,
the more energy that is required to break apart the nucleus of the atom and hence the more stable the nucleus is!
Give me methods safety and shielding against radiation exposure
keep your distance
limit your time
use shielding
what is activity
The activity of a radioactive sample is defined as the number of nuclei which decay each second
were does terrestrial background radiation come from
1.fallout from nuclear explosions
emissions from nuclear power stations and radioactive waste
2.medical uses – treatment of disease and research
3.use in factories – production lines to check if packets are full or thickness of materials.
4.use at home – luminous watches, gun sights, exit signs, gas mantles, smoke detectors
5.from the food we eat and from water sources
building materials and soil
6.radon gas (more of a problem for colder climates)
what is the highest annual safe level of radiation exposure
The highest annual safe level of radiation exposure is 100 mSv/year.
safety and shielding from radiation exposure
limit time ,increase distance,use shielding
what is the formula of binding energy
E=Δmc2
how to calculate binding energy
Step 1. Calculate the mass defect. This is the:
difference in mass between a nucleus and the sum of protons and neutrons in the nucleus or
difference in mass between an atom and the sum of protons, neutrons and electrons in the atom.
describe the role of a fuel rod in a nuclear reactor
contain the nuclear material which under goes fission releasing energy
what is the function of a control rod in a nuclear reactor
absorb neutrons to control the rate of fission occcuring in fuel rods
what is the role of the moderator in the nuclear reactor
slows down fast neutrons emmited from fission to make them suitable to continue fission chain reaction
what is the role of the coolant in the nuclear reactor
absorbs the energy released by fission events used to power an electric generator
other than death describe the effect of radiation exposure can have on a human
can cause vomiting ,nausea hair loss, skin burns,loss of imune system
describe the role of a radiotracer
a radiotracer is a chemical containing a radiosotope that travels throughout the body
What is a radioisotope
Radioisotopes are radioactive isotopes of an element
