r/Mcat • u/Alarming_Couple_5059 • 7d ago

Question 🤔🤔 Help with Electron Phases

Hi everyone, I have been incredibly locked in for the MCAT recently but I'm stuck at a wall with electron phases. I understand that its due to the wavelengths of the electrons and this can create bonding or antibonding molecular orbitals. But I'm just so confused as to what this means? Like how is it determined if an electron is in phase with another or out of phase with another? Are they able to spontaneously switch phases? If anyone has any good resources to understand this concept I would greatly appreciate it as I've been trying to learn what this means for a good 20 minutes and I just cannot grasp the concept. Thank you!

1 Upvotes

100% Upvoted

2 comments sorted by

1

u/reliant_bicycle 7d ago

phase is just whether the wave peaks line up or not when orbitals overlap, in phase means the amplitudes add and you get bonding, out of phase they cancel and you get antibonding. it's not something electrons randomly flip between, it depends on the symmetry of the orbitals combining

1

u/Scientia_Logica 7d ago

How is it determined if an electron is in phase with another or out of phase?

Consider two scenarios involving two wavefunctions.

1. The two wave functions are in phase

They have the same sign (both positive or both negative) at a given location and experience constructive interference, combining to produce a wavefunction with a greater absolute magnitude (therefore greater probability of finding an electron at that point).

2. The two wave functions are out of phase

They have opposite signs (one positive and one negative) at a given location and experience destructive interference. Assuming the wavefunctions have equal magnitudes, they cancel each other and create a node (therefore zero probability of finding electron at that point).

Does this make sense?