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Why bother with a post grad? Are they even worth it? Have your say! 26-10-2016
1. When an unstable nucleus, X decays by emitting a β– particle...
A ) A increases by 1, Z remains the same
B)A decreases by 1, Z remains the same
C) A remains the same, Z increases by 1
D ) A remains the same, Z decreases by 1
(A= nucleon number. Z=atomic number)

I always thought when a beta minus is emitted the nucleon number stays the same and only the atomic number changes by adding one..but the mark scheme says A) is the answer. Please explain ..
2. (Original post by Jas1947)
When an unstable nucleus, X decays by emitting a β– particle...
A ) A increases by 1, Z remains the same
B)A decreases by 1, Z remains the same
C) A remains the same, Z increases by 1
D ) A remains the same, Z decreases by 1
(A= nucleon number. Z=atomic number)

I always thought when a beta minus is emitted the nucleon number stays the same and only the atomic number changes by adding one..but the mark scheme says A) is the answer. Please explain ..
Okay, I haven't come across this topic before, but clearly there is a mistake in the mark scheme, because the nucleus has one more proton (increase in Z) and one less neutron (A is unchanged due to the changes cancelling out).
3. (Original post by sue99)
Okay, I haven't come across this topic before, but clearly there is a mistake in the mark scheme, because the nucleus has one more proton (increase in Z) and one less neutron (A is unchanged due to the changes cancelling out).
Thank you, i was so worried about this simple question but im glad im not the only one who disagrees with the markscheme

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