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

P4

QuestionAnswer
How can electrons change energy level Absorbing or emitting radiation
What is the atomic number Number of protons
What is the mass number No of protons + no of neutrons
What is an isotope An element with a different number of neutrons
Describe the development of the atom -First atoms were thought to be solid spheres which couldn't be divided -plum pudding model -alpha particle scattering experiment proved that there was a positive nucleus with electrons orbiting is shells James Chadwick proved the existence of neutrons
Describe the alpha particle scattering experiment -alpha particles fired at gold foil -most went straight through -some deflected at angles -only a few bounced off
Define activity The rate at which a source of unstable nuclei decays
Define count rate Number of radioactive counts per second
What are the 4 types of nuclear decay -alpha -beta -gamma -neutron
Describe alpha radiation -helium nucleus -stopped by a peice of paper -strongly ionising
Describe beta radiation -high speed electron -moderatly ionising -absorbed by aluminium
Describe gamma radiation -electromagnetic wave -weakly ionising -absorbed by thick lead
Define half-life The time it takes for the number of radioactive nuclei in a sample to half
Define contamination The presence of radioactive atoms on other materials
Define irradiation Exposure of an object to radiation
Give 2 examples of natural sources of background radiation -cosmic rays -rocks
Give 2 examples of man made sources of background radiation -nuclear accidents -fallout of nuclear weapons testing
What affects a person's level of radiation -job -location
What is radiotherapy High ionising radiation directed at cancer cells to kill them
What are the risks of using radiation -tissue damage -cancers -radiation sickness
Describe the process of nuclear fission -radiation nucleus hit by neutron -neutralises absorbed -nucleus splits into two lighter nuclei -neutralises and energy released -neutralises can cause a chain reaction
Describe the process of nuclear fusion Two light nuclei collide and fuse to form larger nucleus this releases energy
Created by: Liam P
 

 



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