Physics IGCSE question Watch

Announcements

Complete our Clearing survey for the chance to win a £50 Amazon voucher >>

start new discussion reply

Skip to page:

Go to first unread

simply_a_ Δ

Badges: 3

Rep:

Report Thread starter 3 years ago

So one of the questions included "define half life" (2 marks)
I put "the time it takes for half the radioactivity of the radioactive material to half"... would you say that makes sense and would be able to gain the 2 marks?

Damien_Dalgaard

Badges: 14

Rep:

Report 3 years ago

No, the answer is:

The time taken for the amount of radioactive decay to decrease by half

OR

The time taken for half of the radioactive decay present to decay.

With respect, you seem to have waffled, and your definition could be interpreted to mean HALF of the half life!

Look in the cgp guide :d

You doing edexcel?

Neymar27

Badges: 5

Rep:

Report 3 years ago

(Original post by Damien_Dalgaard)
No, the answer is:

The time taken for the amount of radioactive decay to decrease by half

OR

The time taken for half of the radioactive decay present to decay.

With respect, you seem to have waffled, and your definition could be interpreted to mean HALF of the half life!

Look in the cgp guide :d

You doing edexcel?

What about 'time taken for half the mass of a radioactive isotope to decay'?

Damien_Dalgaard

Badges: 14

Rep:

Report 3 years ago

(Original post by Neymar27)
What about 'time taken for half the mass of a radioactive isotope to decay'?

I quote from my revision guide:

"The half - life t(1/2) of an isotope is the average time taken for half of the active nuclei to decay".

If you are not satisisfied look at a past exam question in your exam board and look at the mark scheme answer, you will be sorted then :yep:

Its not mass though is it? I thought it was radioactive matter smh

Neymar27

Badges: 5

Rep:

Report 3 years ago

(Original post by Damien_Dalgaard)
I quote from my revision guide:

"The half - life t(1/2) of an isotope is the average time taken for half of the active nuclei to decay".

If you are not satisisfied look at a past exam question in your exam board and look at the mark scheme answer, you will be sorted then :yep:

Its not mass though is it? I thought it was radioactive matter smh

Must have misread it from the textbook then I guess,,, hopefully one mark anyway for putting a few key words in

simply_a_ Δ

Badges: 3

Rep:

Report Thread starter 3 years ago

Yep I'm doing edexcel :\
Wait, would this definition work "the time it takes for the radioactivity of the radioactive material to half"?

Damien_Dalgaard

Badges: 14

Rep:

Report 3 years ago

(Original post by simply_a_ Δ)
Yep I'm doing edexcel :\
Wait, would this definition work "the time it takes for the radioactivity of the radioactive material to half"?

Yes I would agree with that.

Neymar27

Badges: 5

Rep:

Report 3 years ago

(Original post by Damien_Dalgaard)
Yes I would agree with that.

I found a definition though for it being 'mass' in the Pearson textbook

Damien_Dalgaard

Badges: 14

Rep:

Report 3 years ago

(Original post by Neymar27)
I found a definition though for it being 'mass' in the Pearson textbook

I am doing Physics A2, so maybe the definition is different. Look at a past exam question for your exam board and see what the mark scheme says the definition is.

Neymar27

Badges: 5

Rep:

#10

Report 3 years ago

#10

(Original post by Damien_Dalgaard)
I am doing Physics A2, so maybe the definition is different. Look at a past exam question for your exam board and see what the mark scheme says the definition is.

I'll just leave it lol, incase it's wrong and I then think I've gone down even more lol

Damien_Dalgaard

Badges: 14

Rep:

#11

Report 3 years ago

#11

(Original post by Neymar27)
I'll just leave it lol, incase it's wrong and I then think I've gone down even more lol

simply_a_ Δ

Badges: 3

Rep:

#12

Report Thread starter 3 years ago

#12

(Original post by Damien_Dalgaard)
Yes I would agree with that.

Thank you for the reply :P as you can tell, I still haven't fully grasped the definition of half life and I'm doing paper 2 IGCSE in a couple of weeks xD

Neymar27

Badges: 5

Rep:

#13

Report 3 years ago

#13

Thanks, and im doing IGCSE Edexcel btw

(Original post by Damien_Dalgaard)
gl

Damien_Dalgaard

Badges: 14

Rep:

#14

Report 3 years ago

#14

(Original post by simply_a_ Δ)
Thank you for the reply :P as you can tell, I still haven't fully grasped the definition of half life and I'm doing paper 2 IGCSE in a couple of weeks xD

dw I self taught it and as long as you are confident with the material and do all the past papers you'll go far!

The good thing about half life is that the "half" in its name is relevant to the definition, just

(Original post by Neymar27)
Thanks, and im doing IGCSE Edexcel btw

xD, I did that :P

judezeitoun

Badges: 2

Rep:

#15

Report 3 years ago

#15

(Original post by Neymar27)
I found a definition though for it being 'mass' in the Pearson textbook

yes it did say mass my school uses the pearson book too

turn-to-page394

Badges: 16

Rep:

#16

Report 3 years ago

#16

(Original post by simply_a_ Δ)
So one of the questions included "define half life" (2 marks)I put "the time it takes for half the radioactivity of the radioactive material to half"... would you say that makes sense and would be able to gain the 2 marks?

For igcse edexcel, the mark scheme from past papers gave these definitions:

The time taken (1) for the activity of the radioactive sample to half (1)

The time taken (1) for half of the nuclei / atoms / isotopes to decay (1)

Good luck for the exam btw

simply_a_ Δ

Badges: 3

Rep:

#17

Report Thread starter 3 years ago

#17

(Original post by turn-to-page394)
For igcse edexcel, the mark scheme from past papers gave these definitions:

The time taken (1) for the activity of the radioactive sample to half (1)

The time taken (1) for half of the nuclei / atoms / isotopes to decay (1)

Good luck for the exam btw

Oh wow! Thank you for finding the time to look through the markscheme

turn-to-page394

Badges: 16

Rep:

#18

Report 3 years ago

#18

(Original post by simply_a_ Δ)
Oh wow! Thank you for finding the time to look through the markscheme

Oh no, it's fine - I'm taking the exam too and remembered a question like that from past papers.

Zakariyam10

Badges: 1

Rep:

#19

Report 3 years ago

#19

the time taken for half the amount of radioactive atom to decay

Damien_Dalgaard

Badges: 14

Rep:

#20

Report 3 years ago

#20

(Original post by Zakariyam10)
the time taken for half the amount of radioactive atom to decay

This is the same as what I said.

start new discussion

load page 2 of 2

Skip to page:

Go to first unread

Quick Reply

Submit reply

Attached files

Replying is easier on our app - Click here to download for FREE!

Write a reply...

new posts

University open days

University of Birmingham

Postgraduate Open Day Postgraduate

Wed, 20 Mar '19

find out more
King's College London

Postgraduate Taught Courses - Arts & Sciences - Strand Campus Postgraduate

Wed, 20 Mar '19

find out more
University of East Anglia

All Departments Open 13:00-17:00. Find out more about our diverse range of subject areas and career progression in the Arts & Humanities, Social Sciences, Medicine & Health Sciences, and the Sciences. Postgraduate

Wed, 20 Mar '19

find out more

Poll

Join the discussion

Where do you need more help?

Which Uni should I go to?

How successful will I become if I take my planned subjects?

How happy will I be if I take this career?

How do I achieve my dream Uni placement?

What should I study to achieve my dream career?

How can I be the best version of myself?

Which Uni should I go to? (34)

14.11%

How successful will I become if I take my planned subjects? (21)

8.71%

How happy will I be if I take this career? (50)

20.75%

How do I achieve my dream Uni placement? (34)

14.11%

What should I study to achieve my dream career? (30)

12.45%

How can I be the best version of myself? (72)

29.88%