A DILEMMA! involving the masses of neutron in kg and in amu (1 Viewer)

kooltrainer

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well
1 amu = 1.661x10^-27 kg
but 1 neutron = 1.675x10^-27

so it should have 1.008428657 amu

BUT IN TEXTBOOKS (QUITE A FEW) IT FRIGGEN SAYS 1.008665 amu
WTF!?!
this problematic coz i need to no how to convert in order to answer those mass defects questions ...

sum1 plz explain
 

Graceofgod

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kooltrainer said:
well
1 amu = 1.661x10^-27 kg
but 1 neutron = 1.675x10^-27

so it should have 1.008428657 amu

BUT IN TEXTBOOKS (QUITE A FEW) IT FRIGGEN SAYS 1.008665 amu
WTF!?!
this problematic coz i need to no how to convert in order to answer those mass defects questions ...

sum1 plz explain
Although I can't be bothered to explore this, working backwards from the textbook value you get a mass for the neutron of approximately 1.6754
It is possible the textbooks have simply used a more accurate value for the mass of a neutron.

EDIT: It seems the mass of neutron is actually closer to 1.6749, well, I'm stumped :)

Ah no i got it. 1 amu ≈ 1.6605402x10^-27 kg Try this value.
 
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a-n-d-r-e-w

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Im not sure, just use whatever values they give you on your formula sheet. And if it is really killing you then ring the hsc advice line, but if u do that please post up their answer to it
 

kooltrainer

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a-n-d-r-e-w said:
Im not sure, just use whatever values they give you on your formula sheet. And if it is really killing you then ring the hsc advice line, but if u do that please post up their answer to it
yeh, all they have on the formula sheet is the mass of neutro/proton/electron in terms of kgs ... when u tried to find it in terms of amu. . . it wont be 1.008665 (Which is the correct value) .. .

=/ . . . and so.. if they dun give u the mass of neutron in amu in the exam ... then... i dunno how we're gona calculate mass defect
 

helper

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If you use the data sheet value and the conversion factor from the data sheet, then youwill be marked correctly, if all other working is correct. They will normally supply values in AMUs, if they want you to do it that way.

Otherwise, you can convert any AMU data to kgs and work in the same way.
 

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