Is this a Violation of the Law of Conservation?

  • #1
1,291
0

Main Question or Discussion Point

How come electrons don't lose mass as they radiate a field energy in the form of electromagnetic radiation???
 
Last edited:

Answers and Replies

  • #2
jtbell
Mentor
15,551
3,492


What situation are you thinking of?

When an atom drops to a lower electronic energy level and emits a photon, the atom as a whole (system of electron plus nucleus) loses mass, at least in principle. I don't think this decrease in mass has ever actually been measured because it's so small.

In something like synchrotron radiation, the electron loses kinetic energy. This causes a decrease in "relativistic mass", although what most physicists call "mass" (the invariant mass or "rest mass") stays the same.
 
  • #3
1,006
105


How come electrons don't lose mass as they radiate a field energy in the form of electromagnetic radiation???
They lose kinetic and potential energy instead.
 
  • #4
1,291
0


They lose kinetic and potential energy instead.
Interesting, now isn't energy similar to mass also; so that you can weigh energy in a sense. So wouldn't it henceforth lose mass?
 
  • #5
Matterwave
Science Advisor
Gold Member
3,965
326


This is true for a composite system like jtbell was discussing. If electrons in an atom loses potential energy, the atom should have a smaller mass.
 
  • #6
jtbell
Mentor
15,551
3,492
Potential energy is a property of a system (the atom), not of the individual particles (electron and proton) that make up the system.
 
  • #7
2,193
2
How come electrons don't lose mass as they radiate a field energy in the form of electromagnetic radiation???
As EM photons have no "rest mass" their "emission" from an electron does not change the mass of that electron.
 
  • #8
Matterwave
Science Advisor
Gold Member
3,965
326
Potential energy is a property of a system (the atom), not of the individual particles (electron and proton) that make up the system.
I don't think that distinction is all that rigorous. I don't even think the distinction can be made which object "has" the energy...either the nucleon+electron individually or the atom as a whole...
 
  • #9
2,193
2
To the OP:
In a large sense you are attempting an understanding of "mass"

That's totally fine, but be aware that all we currently know about mass is it's effects.
We DO NOT KNOW what causes it.

Hopefully, LHC experiments can assist in our understanding.
 
  • #10
1,291
0
To the OP:
In a large sense you are attempting an understanding of "mass"

That's totally fine, but be aware that all we currently know about mass is it's effects.
We DO NOT KNOW what causes it.

Hopefully, LHC experiments can assist in our understanding.
I love the way you put that: that we know its effects but not what causes it.
 

Related Threads on Is this a Violation of the Law of Conservation?

Replies
5
Views
2K
Replies
4
Views
919
Replies
14
Views
4K
Replies
1
Views
2K
  • Last Post
Replies
1
Views
5K
  • Last Post
Replies
3
Views
1K
Replies
13
Views
4K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
8
Views
2K
Top