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Beta decay watch

1. I thought beta minus is where a neutron -> proton

So surely there would be too many neutrons and vice versa for beta +
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2. Also for fusion and fission do they both have a decrease in mass?

Which is the mass defect

E= mc^2 so energy is released?

3. Can someone explain ci)
4. (Original post by Super199)
I thought beta minus is where a neutron -> proton

So surely there would be too many neutrons and vice versa for beta +
Beta minus is neutron -> proton, it's where there are too many neutrons

Beta plus is proton -> neutron, it's where there are too many protons

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5. (Original post by Super199)
Also for fusion and fission do they both have a decrease in mass?

Which is the mass defect

E= mc^2 so energy is released?
I believe fusion is an increase in mass while fission is a decrease, not sure though

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6. (Original post by Super199)

Can someone explain ci)
Calculate the mass defect and use e=mc^2

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7. (Original post by Super199)
I thought beta minus is where a neutron -> proton

So surely there would be too many neutrons and vice versa for beta +
Just remember conservation of charge

If neutron -> proton, electron must be released to keep charge neutral (beta minus)

If proton -> neutron, positron must be released to keep charge positive (beta plus)

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8. (Original post by Kyx)
Beta minus is neutron -> proton, it's where there are too many neutrons

Beta plus is proton -> neutron, it's where there are too many protons

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So the thing is wrong?
9. (Original post by Kyx)
Calculate the mass defect and use e=mc^2

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How though? Thats what I did for ii
10. (Original post by Super199)
So the thing is wrong?
Yes

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11. b ii) and c i) are essentially the same question but with different values for the data

b ii) is for a single atom, c i) is for 0.001 kg. you have to multiply the answer for b ii) by something

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12. (Original post by Super199)
How though? Thats what I did for ii
Calculate how many uranium atoms are needed to make 0.001 kg. multiply that by your answer to b ii)

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13. (Original post by Kyx)
Calculate how many uranium atoms are needed to make 0.001 kg. multiply that by your answer to b ii)

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Nah surely not.
14. (Original post by Super199)
Nah surely not.
I think so
15. (Original post by Kyx)
I think so
What numbers have you used?
16. (Original post by Super199)
What numbers have you used?
I'll just do the question now
17. (Original post by Super199)
What numbers have you used?
I got the answer to part b ii) correct.

Then I converted 0.001 kg to u to get 6.02 x 10^23

I divided this by the mass (in u) of the original uranium atom to get 2.55 x 10^21

This multiplied by the answer to b ii) gives 7.65x10^10
18. (Original post by Kyx)
I got the answer to part b ii) correct.

Then I converted 0.001 kg to u to get 6.02 x 10^23

I divided this by the mass (in u) of the original uranium atom to get 2.55 x 10^21

This multiplied by the answer to b ii) gives 7.65x10^10
Wait what numbers did you use here?

6.02 * 10^23 and what else?
19. (Original post by Super199)
Wait what numbers did you use here?

6.02 * 10^23 and what else?
236.053
20. (Original post by Kyx)
236.053
So I now get the workings, but I'm actually struggling to understand what's going on.

Like do you mind explaining each step?

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