How do two electrons reside in the same orbital?

Question

Electrons should repel each other but what causes them to overcome the strong repulsive force and remain together?

Answer 1

That's just the way it is. A single proton and a single electron make up the H atom, but this atom is rare because nuclae tend to build electron shells, two electrons make up the K shell of all atoms. Two H atoms unite to form a molecule of hydrogen, in this manner they share two electrons. This not a very scientific answer, but that's the way it is.    

Answer 2

1.due to spin quantum number they reside in opposite direction.

Answer 3

They don't stay together, we don't think.  They spread out over the orbital.  This is a quantum thing.  Think of it as a "fog" that can have a charge of minus 2,  There is "room" for 2 electrons in that fog.

Answer 4

The coulomb attraction between the electrons and the nucleus overcomes the mutual repulsion between electrons.  The repulsion, however, does screen the electrons somewhat from the nuclear charge.  It's similar to what happens when you dig a hole deep in the earth.  The mass "inside" of you matters, the mass "outside" doesn't.  So electrons are screened by all the other electrons INSIDE of them.  Consequently, the valence electrons can be loosely bound, especially if there's only 1 or 2 of them way out there.  This screening results in all the interesting periodic features you learn in chemistry.

The reason that exactly two electrons can be in the same orbital (and not more) is the Pauli exclusion principle.  Particles with spin 1/2 can only stack up one-per-state.  There are two spin states (z component of spin +1/2 or -1/2--up or down) available, so exactly two electrons can be in the orbital.

Answer 5

as far as im concerned, there are two foces acting on the electrons (namely 1-centripetal force, which pulls electrons towards the centre-nucleus,2-centrifugal force, which directs electrons away from the nucleus)which both together keep the electrons stay at their place and finally the atom is stable...

sorry if i couldnt give you the right answer.

Answer 6

the answer is in the realm of quantum mechanics...

not just coulomb forces.  the electrons aren't orbiting in a classical sense or anything like that.  they just exist in possible shells.

i cant remember exactly how it was but you use the schrodinger equation and the potential given by the nucleus of the atom... on finding a solution all the quantum numbers and stuff emerge.  

anyway, the answer is not so simple.  the electrons are in different quantum states (pauli exclusion principle) due to different spins, so they can occupy the same shell without being in the same state