proton electron pair

[Ankit Gupta]

Why do an electron never stick to its nucleus I mean both opposite charges attract each other but why they never stick to each other (like in Bohr's model) ?

[Sensei]

Never?

Nucleus can absorb electron.
It happens when nucleus is proton-rich.

Process is called electron capture.
http://en.wikipedia.org/wiki/Electron_capture

Either electron and proton are fermions.
http://en.wikipedia.org/wiki/Fermion

Pauli exclusion principle
http://en.wikipedia.org/wiki/Pauli_exclusion_principle
"The Pauli exclusion principle is the quantum mechanical principle that no two identical fermions (particles with half-integer spin) may occupy the same quantum state simultaneously."

ps. "sticking to something" is rather macroscopic term.

Edited November 29, 2013 by Sensei

[Ankit Gupta]

Never?

 

Nucleus can absorb electron.

It happens when nucleus is proton-rich.

Process is called electron capture.http://en.wikipedia.org/wiki/Electron_capture

 

Either electron and proton are fermions.http://en.wikipedia.org/wiki/Fermion

 

Pauli exclusion principlehttp://en.wikipedia.org/wiki/Pauli_exclusion_principle

"The Pauli exclusion principle is the quantum mechanical principle that no two identical fermions (particles with half-integer spin) may occupy the same quantum state simultaneously."

 

ps. "sticking to something" is rather macroscopic term.

ya I knew that but i thought that there would be some thing more than that but OK tkanks

[Enthalpy]

In the usual atoms, electrons stick already as much as they can to the nucleus. The atom's diameter is the size of the electrons, which can't be zero because electrons are waves.

 

What you've pointed at was a fundamental flaw of the classical image of particles as points, which would lead them to fall on the nucleus. Quantum mechanics was introduced to solve this point and some more, and has done it brilliantly.

 

I've written "the size of the electron", and this is a bit provocative... The electron has no fixed size and can be detected as one single particle in a volume as small as Mankind can achieve - but an atom nucleus confines the electron using limited means, which are the electric charge of a few protons, and the resulting confinement is an atomic diameter.

 

 

"The Pauli exclusion principle is the quantum mechanical principle that no two identical fermions (particles with half-integer spin) may occupy the same quantum state simultaneously."

A proton and an electron are not identical particles, so the exclusion principle does not apply.

[swansont]

Why do an electron never stick to its nucleus I mean both opposite charges attract each other but why they never stick to each other (like in Bohr's model) ?

 

It's generally not energetically favorable for them to combine (if it is, electron capture is possible, as described above). If they don't combine, the Heisenberg uncertainty principle tells us that the electron can't be confined to such a small region.