Proton vs Neutron: Mass Comparison

[colinr]

isn't a neutron more massive thatn a proton?

 

[Atheist]

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]

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]

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]

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]

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]

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]

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]

What, the *** are you guys talking about ?

regards
marlon

 

[humanino]

They are trying to make us swallow that a neutron = a proton + an electron :tongue2:

 

[marlon]

Based upon what evidence ?

What is the underlying theory here ...

regards
marlon

 

[humanino]

That would simply be wrong.