Results are out! Find what you Get quick advice or join the chat
Hey! Sign in to get help with your study questionsNew here? Join for free to post


Announcements Posted on
The Grow your Grades contest is here, join in to help each other achieve your study goals 22-01-2015
  1. Offline

    Click image for larger version. 

Name:	physics.png 
Views:	21 
Size:	139.3 KB 
ID:	157061

    One of the answers in the mark scheme is "Half-life long enough to emit over a few years" - but the americium sample has a half life of 432 years so how can it only emit over a few years?
  2. Offline

    It means you don't want to use a sample that decays quickly as pretty soon it will be useless, by using a sample with a longer half-life the sample remains useful for longer. Obviously 432 years is much longer than any detector is required to last and so there will be no worries about the sample decaying away significantly during the detectors lifetime.


Submit reply


Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. By joining you agree to our Ts and Cs, privacy policy and site rules

  2. Slide to join now Processing…

Updated: June 14, 2012
New on TSR

Everyday things you can't do

Why do they make everything so difficult?

Article updates
Quick reply
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.