Past papers help...(Radioactivity)

[VelaneDeBeaute]

I was stuck at this one...did it but in Q8 part a were v supposed to draw curves? It wud b gr8 if sum1 put up an img demonstrating it..! I too want the ans to its b(2)..i think its 10 yrs..!
http://www.xtremepapers.me/CIE/Cambridg ... 2_qp_2.pdf

Last Q of this ppr...c(1) part.!
http://www.xtremepapers.me/CIE/Cambridg ... 3_qp_2.pdf

Thanx in adv..!

 

[Silent Hunter]

wese how did u do part b(ii) ?

yes they are curves i think

asnwer to the second paper is 2000 years approx.....may vary from paper dimensions

method:
quires the
candidate to convert the counts from 380 per hour to 6.3 per second and then read the answer
from the graph.

 

[Maleeha]

i have drawn the curves for (a) part.. now how to upload them??????
answer to (bi) is 40 n yes to (ii) is 10 years.. confirmed.

 

[Maleeha]

ghalya im sending the answers on fb..ok?? cuz i cant get how to upload em here.

 

[Jinkglex]

http://www.xtremepapers.me/CIE/Cambridg ... 4_qp_1.pdf

guys, check out the MCQ number 39 in this page. The answer is given C, but isnt alpha particle 2 protons? shouldnt it go down from 90 to 88?

 

[Maleeha]

but it first emits two beta particles that make its proton no. go up to 92 n then it comes back to 90 with emission of alpha particle

 

[BaKa]

i didn't get it? i understood the 140 part but how come the number goes to 92???

 

[izzahzainab]

first the atom loses two beta particles, so its proton number becomes 92. then it loses an alpha particle and proton number becomes 90. hope it helped

 

[BaKa]

how does it become 92 that is the total confussion and law how???????????????????????????????

 

[leosco1995]

The charge on a beta particle is -1, it will increase the proton number by 1. Since it does this twice, it goes to 92. Then the alpha particle has a charge of +2 and makes it go back to 90.

 

[VelaneDeBeaute]

Everyone...thanx 4 helping...! :Bravo: