Assignment Details

Half-Life Worksheet

Year 2024-25

10GH-Physics - (m5+6 / fr-rotation)

Date Due

Sept. 20, 2024, 8:30 a.m.

Additional Info

To make things a bit easier, I've added an easier worksheet to try first...

Remember, the "Half life" of a substance is the time it takes for the 'amount', or the 'activity/decay-rate' to halve from an initial value.

On OneNote, in;
Unit 7 > Lesson 02

COMPLETE;
  • 2a - Half Life - Entry level Activity sheet
THEN TRY
  • 1 - Half-Life Worksheet - ONLY TRY Q1-3... Please read the hints for each question (below) first if you are stuck....
    • Questions 1 ; After each half life the count rate will half (e.g. after 1 half life 800Bq will half to 400Bq, after 2 half lives it will halve again to 200Bq, and so on...)
    • Question 2 ; notice that all the questions are just multiples of '5.3 years', in other words, each question is asking what the activity will be after a certain number of half lives, just like question 1, with the additional initial step that you must first work out how many half lives (how many times 5.3 years) fit into the time passed in the question
    • Question 3 ;  Initially the bone has 24g of Carbon-14.  Every year, the amount of Carbon-14 will half.  
      • Step 1; work out how many times you have to half 24g to get the mass of carbon in the question (e.g. for part (a) 24 must be halved 3 times to get to 3g (24g --> 12g --> 6g --> 3g), so THREE HALF LIVES have passed.
      • Step 2 ; If each half life is 5700 years, just multiple the value found in step 1 by 5700 to find the age of the bone.
If you have any of your 30min hwk time remaining...
    • You could try Q4-6 if you find the basic questions easy, but we will look at these in more depth next lesson, so don't worry if you don't get on to them!!!
    • DO NOT DO Q7 and Q8 yet!!!!