The Naked Scientists

The Naked Scientists Forum

Author Topic: Why do atoms bind together?  (Read 2670 times)

Offline Eric A. Taylor

  • Sr. Member
  • ****
  • Posts: 447
  • I before E except after C, unless weird science
    • View Profile
Why do atoms bind together?
« on: 11/08/2010 16:27:07 »
The electromagnetic force is so strong it keeps atoms (witch are almost entirely empty space) in solid matter from passing through each other. So why do they stick together to form molecules?

Conversely, what prevents the electrons from being attracted to, and binding with protons (to form neutrons)?


 

Offline Soul Surfer

  • Neilep Level Member
  • ******
  • Posts: 3345
  • keep banging the rocks together
    • View Profile
    • ian kimber's web workspace
Why do atoms bind together?
« Reply #1 on: 11/08/2010 23:43:52 »
The shells of electrons around atoms makes them try to repel each other but the presence of a positively charged nucleus reduces this repulsion effect.  atoms which have complete shells of electrons.  The noble gasses do not bond together.  Most atoms however have incomplete shells of electrons and this lack of completeness leaves holes where the attraction of the nucleus can overbalance the repulsion of the other electrons and atoms that have a complementary excess of electrons can fit into these gaps and form compounds.

Just adding an electron to a proton does not produce a neutron the electron has to interact with one of the quarks via the weak interaction process involving  the generation of a W boson (which is very heavy) to change it into a different sort of quark so there is a big barrier to this happening.  In fact neutrons in isolation are unstable and will decay into protons with a half life of around 15 minutes.  because a neutron on its own has slightly more energy than a proton and an electron separately. When neutrons are in nucleii this does not in general happen because the binding energy of the nucleus via the streong inteaction orevents it but in certain atoms containig an excess of neutrons  this can happen and it is called beta decay (qv).
 

The Naked Scientists Forum

Why do atoms bind together?
« Reply #1 on: 11/08/2010 23:43:52 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums