Two Questions

[newbie2k6]

Hello,

I want to ask u guys two questions

Q.The two electrons in S-orbital acquires same energy or different energy and WHY?

 

Q.What is the difference between Dalton's theory, Bohr's theory and Quantum theory

 

Thanks

[Zilali]

The second electron to enter the S orbital is said to be at a lower energy level than the first. This is due to the fact that electrons of opposite spin will repel each other and becasue the S orbital can only hold two electrons, the second electron will enter the orbital already occupied.

 

As the two electrons repel each other, the valence electron is significantly easier to remove therfore lowering is energy level. This also explains why the first ionisation energies of elements going across a peroid drop when going from group I to group II.

[HydrogenBond]

The S orbital contains two electrons. In the case of the hydride anion H-, the electrons will have opposite spin and motion. The EM force is the integration of the electrostatic and magnetic forces. The magnetic addition due to the two opposite spin and opposite motion electrons shifts the EM force within the S orbtial away from negative charge repulsion, toward magnetic addition, allowing the single hydrogen proton to hold the two electrons without them repelling each other away.

 

If we add some energy to the system, we will disrupt the magnetic addition (changes the location of one or both electrons) causing the EM force to shift back to the electrostatic repulsive force. One possbile result is the loss of one of the electrons. The higher electrostatic potential of the remaining electron, due to the loss of magnetic addition, keeps it closer to the proton.