[ktoto]

I have two questions:

    1. Say that Carbon, before being bonded to 4 H atoms needs to have 4 sp^3 hybrid orbitals. sp^3 is created by 3 p orbitals and 1 s orbital. However, elec. conf. of Carbon is 1s^2 2s^2 2p^2, meaning that it has two 2p orbitals. Question: does an 2s electron need to be in exited state (in a 2p orbital) so that carbon actually has 3 2p orbitals in order for the 4 sp^3 orbitals to form?

    2. In molecular orbital theory, a molecule forms two types of orbitals when a bond forms: the bonding hybrid orbital and the antibonding hybrid orbital. The bonding hybrid orbital is lower in energy so that ground state electrons occupy only that orbital. Does this mean that when the molecule is in exited state and its electrons jump to the antibonding orbital the molecule becomes unstable and falls appart?

[Borek]

elec. conf. of Carbon is 1s^2 2s^2 2p^2, meaning that it has two 2p orbitals.

Hopefully you mean "it has two electrons occupying two of the three 2p orbitals"

[Yggdrasil]

I have two questions:

    1. Say that Carbon, before being bonded to 4 H atoms needs to have 4 sp^3 hybrid orbitals. sp^3 is created by 3 p orbitals and 1 s orbital. However, elec. conf. of Carbon is 1s^2 2s^2 2p^2, meaning that it has two 2p orbitals. Question: does an 2s electron need to be in exited state (in a 2p orbital) so that carbon actually has 3 2p orbitals in order for the 4 sp^3 orbitals to form?

The other p orbital is still there just unoccupied.  For example, your bedroom still exists even if no one is in the bedroom and no one can see the bedroom.

2. In molecular orbital theory, a molecule forms two types of orbitals when a bond forms: the bonding hybrid orbital and the antibonding hybrid orbital. The bonding hybrid orbital is lower in energy so that ground state electrons occupy only that orbital. Does this mean that when the molecule is in exited state and its electrons jump to the antibonding orbital the molecule becomes unstable and falls appart?

Excellent question and excellent answer.  Yes, this is exactly what happens.  This phenomenon is the basis for many photochemical reactions.  For example, UV light can break the Br-Br bond in bromine to generate bromine radicals.

[english]

Generally speaking, one of the 1s electrons gets promoted to the empty 2p orbital.

I don't know exactly how this phenomenon occurs so I could not give an explanation. 


Also, if equal numbers of electrons fill bonding and antibonding MOs, there is no bond.  This is another way of saying that some species cannot exist, such as He₂.

[Ψ×Ψ]

Generally speaking, one of the 1s electrons gets promoted to the empty 2p orbital.

I'd think that it would be a 2s to 2p transition...
It seems weird to think of exciting atomic carbon anyway.  Anyone know if this has been done, maybe in gas phase?

[english]

Generally speaking, one of the 1s electrons gets promoted to the empty 2p orbital.

I'd think that it would be a 2s to 2p transition...
It seems weird to think of exciting atomic carbon anyway.  Anyone know if this has been done, maybe in gas phase?

Yes thank you for that correction.  I meant 2s.  Silly me.   

[xiankai]

I'd think that it would be a 2s to 2p transition...
It seems weird to think of exciting atomic carbon anyway.  Anyone know if this has been done, maybe in gas phase?

maybe it is an intermediate reaction, such that it only lasts for a short while to form the sp³ orbitals. as to its existing on its ownself, im not sure either

[vhpk]

About the orbitals, I have one question:
Why is Cu²⁺  stronger than Cu⁺ while its configuration( 3d⁹) is weaker than the configuration of Cu⁺ (3d¹⁰⁾)

[vhpk]

About the orbitals, I have one question:
Why is Cu²⁺ stronger than Cu⁺ while its configuration( 3d⁹) is weaker than the configuration of Cu⁺ (3d¹⁰⁾)

Noone has  idea

[Borek]

If you could explain what you mean by stronger and weaker when you refer to ions and orbitals it may be easier to get what you are asking about.

But I think I know what you are aiming at. Don't forget that Cu²⁺ stability in aqueous solutions is enforced by water moilecules that complex the ion. So in fact what is stable is not just Cu²⁺, but Cu²⁺/H₂O complex.