Karteikarten
Physics: Chapter 20: Atomic Physics
Karten in diesem Stapel (42)
- 1What does the nucleus of an atom contain?Protons and neutrons
- 2State the charges of protons, neutrons and electronsprotons +1
neutrons no charge
electrons -1 - 3What was Rutherfords experiment?A thin gold foil is bombarded with alpha particles which are positively charged
- 4What were the results of Rutherford scattering conclusions for most helium nuclei?Most Helium nuclei pass through with very little or no deflection which shows the nucleus is very small and atoms are mostly empty space.
- 5What were the results for some?Some repelled so strongly were bounced back or deflected at large angles - mass concentrated in nuclus experience a force, atoms have a positive charge
- 6What were the overall resultsThe atom must be largely empty space, with its positive charge and most of its mass concentrated in a tiny nucleus.
- 7Isotopesatoms of the same element that have different numbers of neutrons eg carbon 12 and carbon 14
- 8Radio isotopesUnstable atoms, which break down giving radiation
- 9What are the the medical uses of radio isotopes?Cancer treatment (radiotherapy) - rays kill cancer cells using cobalt-60
- 10What are is the industrial and archaeological uses of radio isotopes?Check for leaks - use Geiger counter
Archaeological use: Carbon 14 used for carbon dating - find appropriate age of object made from dead organic material - 11Radioactive decayA radioisotope is altered to make a more stable arrangement. The parent nucleus becomes a daughter nucleus and a particle - decay products
- 12What process is Radioactive decay?Random
- 13Ionizing radiationCauses the particles they come into contact with to become ionized - electrically charged by losing or gaining electrons
- 14Alpha decayAn element with a proton number 2 lower and nucleon number 4 lower and an alpha particle is made 2protons + 2 neutrons
4 2 HE - 15Beta Decayan element with the same nucleon number but with a proton number 1 higher.
0 -1 B - 16Gamma EmissionCauses no change in mass or atomic number however emit energy as their particles rearrange themselves to become more stable
0 0
nucleus stays same - 17What are the natures of alpha, beta and gamma emissions?a - helium nucleus
b one high speed electron
y electromagnetic radiation - 18What are all their charges?a +2
b -1
c none - 19Penetrationa stopped by paper and 10cm of air
b stopped by aluminum .5cm of lead
y reduced by lead (30cm of concrete) - 20Nuclide notation of eacha 4 2 a +2
b 0 -1
y 0 0 - 21Relative mass of eacha 4
b 0
y 0 - 22Ionizing powera high
b medium
y low
Ionizing power - interact with others so lose energy fast - 23speed of eacha 1/10v of light
b 1/10v of light
y v of light - 24Particle or wave for eacha particle
b particle
y wave - 25What are the uses of each?a - smoke detectors
b - factory measure thickness of paper
y - trace blood flow - image organs, sterilization - medical equipment - kill bacteria and virus - 26Give a diagram of the 3 radioactive emissions in a magnetic field
- 27noteb particles start changing before alpha. with bigger deflection
same for electric field - 28Half Lifeaverage time taken for the count rate of a radioactive sample to half
- 29Nuclear fissionSplits 1 nucleus into 2 or more smaller nuclei. It usually happens in a nuclear reactor
uranium -235 - 30Nuclear FusionFuses 2 smaller nuclei to create 1 larger nucleus - creating this releases energy
- 31Are these fusion or fission? Atomic bombs Hydrogen bomb StarsAtomic bombs - fission - chain reaction from fission releasing more neutrons
Hydrogen bomb - fusion
Stars - fusion of hydrogen and helium nuclei - 32How do you calculate substance radiation?Total radiation - background radiation
- 33What bad things can ionizing radiation do?Can damage DNA in the cell nucleus of living things causing mutations. Mutated cells may divide uncontrollably and a tumour forms - how some cancers are formed. Damaged DNA can also be passed along by reproduction if the cell is a gamete. An extremely high dose of radiation can kill cells and cause radiation burns.
- 34How dangerous are alpha sources?relatively harmless outside the body as can't penetrate dead skin. However inside the body can cause the most damage as most ionizing
- 35What are methods of protection for handling radioactivity substances safely?rubber gloves, radiation suits and masks, x-ray screens (lead), limiting exposure
- 36How do you store radioactive sources?Store in containers lined with lead.
used nuclear fuel is first kept in a spent fuel pool where water absorbs most of the radiation. - 37Background radiationsmall amount of radiation around us all the time because of radioactive materials in the environment.
- 38What are the main sources of background radiation?food
rocks
radon gas
sun - 39What do you need to do first when finding the count rate of a radioactive source?Remove background radiation count rate
note background radiation is random and spontaneous - 40What can be used to find the background radiation?Over a several minutes use Geiger counter and calculate average
- 41How does a Geiger-Muller (GM) tube work?detects a, b and y
has window thin enough for alpha particles to pass through. If detect radiation, the radioactive emission ionizes the gas inside the tube. This sets off a high-voltage spark across the gas and a pulse of current in the circuit, Can be connected to a rate meter or scaler (measures how many) loud click when radiation detected - 42What is a formula to calculate a half life.An = A/2>n
n = number of half lives
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- GCSE Science (Physics) Karteikarten am Physics: Chapter 20: Atomic Physics, erstellt von HRYN red am 24/02/2021.
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