Question

what causes the nucleus of an atom to weigh less than the sum of its isolated component particles?

Answer 1

E=mc^2

Answer 2

Nuclear fission

Answer 3

\[∆E = ∆m c^2\]

Answer 4

a change in energy as it becomes more stable, the mass decreases?

Answer 5

The nucleus of an atom splits into smaller parts, producing free neutrons and photons. Hence \(E=mc^2\), and releasing a very large amount of energy. The masses are typically with a mass ratio of products of about 3 to 2,

Answer 6

It's called the "mass defect" - see: http://en.wikipedia.org/wiki/Binding_energy

Answer 7

I know what it is called, but what causes the phenomena to occur is what I need a little bit of information on. I understand how the equation of relativity easily explains it, but it does not account that gluons are supposedly massless.

Answer 8

am I just talking nonsense trying to delve into this by missing some fundamentals?

Answer 9

The mass of the gluons don't matter. They are force-carriers.
What matters is the difference in energy between bound particles and unbound.

Answer 10

thanks cliff.

Answer 11

Some of the fundamentals are that particles always seek the lowest potential energy configuration. In a stable nucleus, the potential energy is lower than if the particles were separate (because there is a force of attraction due to the gluons). With increased separation, the force is able to do more work and the potential energy increases.
This is analogous to lifting an object against a gravitational field, the potential energy increases.

For nucleons that fission from a nucleus, the increase in potential energy is seen in the form of increased mass (because mass and energy are kinda the same thing.)

Answer 12

from what I gathered, you are suggesting that potential energy has something to do with increased or decrease in mass.

Answer 13

E=mc^2

Answer 14

lol thanks i knew that it'd come back to that

Answer 15

"energy"

Answer 16

Consider this for extra silliness:
Quarks tend to come in bound pairs or triplets. The energy of attraction between quarks is so large that if you attempt to separate two quarks, the amount of energy required will create two more quarks.

Answer 17

i learned that from Neil deGrasse's lectures.

Answer 18

Nice. :-)
I recommend some Lawrence Krauss too.

Answer 19

I know. I was looking at Krauss' book and his past works, but right now I am bogged down with too much stuff for me to be able to sit down and digest it fully.

Answer 20

thanks for your help.