Save
Busy. Please wait.
or

show password
Forgot Password?

Don't have an account?  Sign up 
or

Username is available taken
show password

why


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.


Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
focusNode
Didn't know it?
click below
 
Knew it?
click below
Don't know (0)
Remaining cards (0)
Know (0)
0:00
share
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Science P2 Topic 5

Edexcel GCSE additional science physics: nuclear fission and fusion

QuestionAnswer
What are nucleons? sub-atomic particles within the nucleus i.e. neutrons and protons
What is the atomic number of an element? It is the number of protons in an atom of the element, and is equal to the number of electrons
What is the mass number of an element? The number of nucleons (neutrons + protons) in an atom of the element
How do you work out the number of neutrons in an element? Mass number - atomic number
What are isotopes? Atoms of a single element with different numbers of neutrons (making the mass number different) e.g. lithium-6 and lithium-7
What is ionising radiation? Radiation that has enough energy to make atoms lose electrons to become positively-charged ions
What is radioactive decay? The random process where an unstable nucleus in a radioactive material decays by releasing ionising radiation to become more stable
What are the features of the 3 types of ionising radiation? 1) alpha particles- very ionising, stopped by paper, emitted from nucleus, 2 protons + 2 neutrons 2) beta particles- electrons emitted from a nucleus, stopped by a few mm of aluminium 3) gamma rays- electromagnetic waves, stopped by lead/concrete
What are some dangers of ionising radiation? Can cause skin burns (reddened skin) and can mutate DNA inside cells causing cancer
What is nuclear fission? The process where a large, unstable nucleus splits into two smaller, daughter nuclei - neutrons are released as well as a lot of energy (thermal and kinetic)
What is the difference between a controlled and uncontrolled nuclear chain reaction? Uncontrolled: lots of neutrons are released from each fission reaction which cause even fission and will result in an explosion. Controlled: another material is present to absorb all neutrons bar 1, so only 1 is absorbed by another nucleus
How does a nuclear reactor keep a controlled nuclear reaction? Control rods are present- they contain elements that absorb extra neutrons, and they can be lowered into the core to decrease fission levels and raised out to increase the levels
What is the purpose of the following features of a nuclear reactor core: concrete shielding, fuel rods, moderator? Concrete shielding- prevents stray neutrons and radiation escaping. Fuel rods- contain pellets of radioactive fuel e.g. uranium, plutonium. Moderator- slows neutrons down so they are more likely to be absorbed
How is the thermal energy released by nuclear fission used to generate electricity? A coolant (water at high pressure) is pumped through the core and becomes superheated- it's pumped to a heat exchanger where it is used to produce steam, which drives a turbine and turns a generator that transfers kinetic energy into electrical energy
What are some advantages of using nuclear power to generate electricity? * there is currently a large supply of radioactive fuel * no greenhouse gases are released
What are some disadvantages of using nuclear power to generate electricity? * expensive to build and decomission * constant danger of radioactive materials escaping * waste has to be buried safely for a long time * energy to create fuel rods was probably produced in a way that released greenhouse gases
What is nuclear fusion? the process whereby two smaller nuclei fuse to become one larger one, and lots of energy is released
How do stars get their energy? Nuclear fusion
What conditions are needed for nuclear fusion? * high pressures to increase densities of the nuclei, allowing them to get closer to each other and collide more easily * they need to be at a very high temperature to allow them to travel fast and overcome electrostatic repulsion
Why is electrostatic repulsion a problem? • These conditions are hard to sustain on Earth so producing fusion power is very difficult
What is the peer-review process? where scientists repeat the experiments done by another scientist and they must get the same results to validate the evidence e.g. this failed for the theory of 'cold fusion'
Created by: 11043
 

 



Voices

Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!

"Know" box contains:
Time elapsed:
Retries:
restart all cards