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colinr
Sep4-04, 08:29 PM
isn't a neutron more massive thatn a proton?

Atheist
Sep4-04, 08:49 PM
It is. Free neutrons are even unstable and decay with a lifetime of something like 12min. To my big surprise, when I looked it up, the mass-difference was much more than I expected: 2.5 times the mass of an electron (I expected not much more than the electron mass).

Tom McCurdy
Sep5-04, 12:25 AM
The neutron is about 0.2% more massive than a proton, which translates to an energy difference of 1.29 MeV. I believe that the added mass of the electron plus the proton equals very close to the mass of the neutron.

ArmoSkater87
Sep5-04, 12:39 AM
It is. Free neutrons are even unstable and decay with a lifetime of something like 12min. To my big surprise, when I looked it up, the mass-difference was much more than I expected: 2.5 times the mass of an electron (I expected not much more than the electron mass).

This is impossible, the mass of the proton is 1.67262158 × 10-27 kilograms, while the mass of the electron is 9.10938188 × 10-31 kilograms. This means that the proton has a mass more than 10^4 times that of the electron.

colinr
Sep5-04, 07:50 AM
How come when a proton turns into a neutron (as in nuclear fusion in the Sun) it gives out energy AND gains in mass, where does all the extra energy come from

Atheist
Sep5-04, 08:30 AM
Masses given for particles are the masses of free particles. When particles bond together the created particle can have a lower mass than the sum of the constituents (to some extend one can even see this as the reason why stable bound states exist). The mass-difference is called the bonding energy.

@ArmoSkater: You seem to have mistaken my 1st post.

Tom McCurdy
Sep5-04, 11:28 AM
here this site should help in finding about the decay of the neutron and about both the neutron and proton in general

http://hyperphysics.phy-astr.gsu.edu/hbase/particles/proton.html

Chaotic42
Sep5-04, 03:29 PM
This is impossible, the mass of the proton is 1.67262158 × 10-27 kilograms, while the mass of the electron is 9.10938188 × 10-31 kilograms. This means that the proton has a mass more than 10^4 times that of the electron.

I think he means that he thought the difference in mass between a neutron and a proton would be close to the mass of an electron.

marlon
Sep10-04, 09:43 AM
What, the *** are you guys talking about ???

regards
marlon

humanino
Sep10-04, 10:42 AM
They are trying to make us swallow that a neutron = a proton + an electron :tongue2:

marlon
Sep10-04, 01:19 PM
Based upon what evidence ???

What is the underlying theory here ...

regards
marlon

humanino
Sep10-04, 01:44 PM
That would simply be wrong.