Excuse me again, but I am afraid that it is not the electrons forth-and-back into 3s lower and higher zone (occupied and unoccupied zones) that creates current (@ around 9:05). The current is being created by the flow of electrons at the opposite the direction of the applied Electric Field. That means that a flowing electron is already in the conduction band. So, could you please tell us where is the conduction and the valence band in your diagram?
Unless you mean the collisions that an electron faces with the atoms when it flows due to Electric Field appliance (current production). That means that it starts from the 3s of an atom, then escapes due to Potential applied and then as it flows inside the metal (still in conduction zone) it gets attracted by another atom and into its 3s (you know, for a very very short period of time). It is not clear what is meant here! I think that a part of the applied Potential energy is consumed to provide sufficient energy to the electron to escape the valence zone and jump into conduction zone, no? Isn' t this the mechanism? Then the rest of the energy attracts the electron towards the Anode (of a battery, for example). No? Not sure!
Yes, I think that it happens so, because you say: "This means that when we apply a voltage across the metal, these electrons increase in energy and jump to these empty quantum states.". So up to here we agree. I think that it is not quite clear which are "these empty quantum states". I will retry to watch the video.
It seems that these empty quantum states are the 3s unoccupied states (@ 8:30). I think that the 3s unoccupied states are the potential barrier (@7:50), that is, the 3s unoccupied state is the Valence's upper Region.... Could you please tell us where the potential barrier ends? Your finger pointing is not ... you know... accurate. Is it where the atom well ends (upper point of the curvatures) or is it where E = U = 0? Also, is where the potential barrier ends the lower energy level of the E_conduction zone? I think that 3s zone corresponds to E_valence of the metallic Na volume. Thanx!
from pauli´s exclusion principle - yes. they form a band because of orbital overlap. if you bring 2 orbitals with same symmetry (this case s orbitals) close together they form a bonding s (lower E) and antibonding s* (higher energy). do it with another pair and you get a bonding s and also an antibonding s*. now you can consider the bonding and antibonding orbitals the same way like the s orbital and they start forming a band when a shit ton of them do it.
Pawan Kandel if we apply some potential in the metal ,,this energy is in the form of K.E and by taking this outermost electron can jump (drift)and constitute current
In this example, why do the electrons in the atoms' 3s bands have different energies when combined? Presumably, their energies are equivalent when the atoms are separate, but why do they become different when combined? I understand the Pauli Exclusion Principle, but what is the physical mechanism which compels them to occupy slightly different energy levels? Is it because they can't physically occupy the same level, lest they smash into each other? Do the atoms smash into each other a bit in the beginning, and ultimately settle into paths where they don't smash into each other? Why don't they just continuously smash into each other?
This guy has a fantastic lecturing style. His speech is so clear and the methodical manner in which he presents the topic is fantastic. Well done.
Excuse me again, but I am afraid that it is not the electrons forth-and-back into 3s lower and higher zone (occupied and unoccupied zones) that creates current (@ around 9:05). The current is being created by the flow of electrons at the opposite the direction of the applied Electric Field. That means that a flowing electron is already in the conduction band. So, could you please tell us where is the conduction and the valence band in your diagram?
Unless you mean the collisions that an electron faces with the atoms when it flows due to Electric Field appliance (current production). That means that it starts from the 3s of an atom, then escapes due to Potential applied and then as it flows inside the metal (still in conduction zone) it gets attracted by another atom and into its 3s (you know, for a very very short period of time). It is not clear what is meant here! I think that a part of the applied Potential energy is consumed to provide sufficient energy to the electron to escape the valence zone and jump into conduction zone, no? Isn' t this the mechanism? Then the rest of the energy attracts the electron towards the Anode (of a battery, for example). No? Not sure!
Yes, I think that it happens so, because you say: "This means that when we apply a voltage across the metal, these electrons increase in energy and jump to these empty quantum states.". So up to here we agree. I think that it is not quite clear which are "these empty quantum states". I will retry to watch the video.
It seems that these empty quantum states are the 3s unoccupied states (@ 8:30). I think that the 3s unoccupied states are the potential barrier (@7:50), that is, the 3s unoccupied state is the Valence's upper Region.... Could you please tell us where the potential barrier ends? Your finger pointing is not ... you know... accurate. Is it where the atom well ends (upper point of the curvatures) or is it where E = U = 0? Also, is where the potential barrier ends the lower energy level of the E_conduction zone? I think that 3s zone corresponds to E_valence of the metallic Na volume. Thanx!
does energy of each sodium atom 3s eletron differ so they form band together
from pauli´s exclusion principle - yes. they form a band because of orbital overlap. if you bring 2 orbitals with same symmetry (this case s orbitals) close together they form a bonding s (lower E) and antibonding s* (higher energy). do it with another pair and you get a bonding s and also an antibonding s*. now you can consider the bonding and antibonding orbitals the same way like the s orbital and they start forming a band when a shit ton of them do it.
How does shift of electrons in 3s unoccupied orbital help in current flow?
Pawan Kandel if we apply some potential in the metal ,,this energy is in the form of K.E and by taking this outermost electron can jump (drift)and constitute current
In this example, why do the electrons in the atoms' 3s bands have different energies when combined? Presumably, their energies are equivalent when the atoms are separate, but why do they become different when combined? I understand the Pauli Exclusion Principle, but what is the physical mechanism which compels them to occupy slightly different energy levels? Is it because they can't physically occupy the same level, lest they smash into each other? Do the atoms smash into each other a bit in the beginning, and ultimately settle into paths where they don't smash into each other? Why don't they just continuously smash into each other?
Thank you
The audio and video are out of sync. Unfortunately it is difficult to follow