C3. Electrons and orbitals Flashcards
what is the secondary quantum number?
Each shell has an n number of subshells, l, which is defined as the secondary / azithmual quantum number
what is the secondary quantum number, I, of the s atomic orbital?
0
what is the secondary quantum number, I, of the p atomic orbital?
1
what is the secondary quantum number, I, of the d atomic orbital?
2
what is the magnetic quantum number?
Each subshell can have a particular orientation in space defined by the magnetic quantum number, ml .
what is the magnetic quantum number for s orbitals?
For s orbitals: l = 0 Therefore ml = 0
what is the magnetic quantum number for p orbitals?
For p orbitals: l = 1 Therefore ml = -1, 0, +1
what is the magnetic quantum number for d orbitals?
For d orbitals: l = 2 Therefore ml = -2, -1, 0, +1, +2
what is the spin quantum number, s?
The spin quantum number, s relates to the angular momentum of an electron. Electrons are either spin up (s = +1/2) or spin down (s = -1/2)
what is Aufbau principle?
Orbitals / subshells filled in order of lowest possible energy
what is Pauli exclusion principle?
Every electron must have a unique spin in each orbital
what is Hund’s rule?
In a half-filled subshell, it is energetically more favourable to have electrons of parallel spins
What does the VSEPR (Valence Shell Electron Pair Repulsion) model state?
The VSEPR model states that electrons in orbitals will arrange themselves so they are as far apart as possible in space.
where does the VSEPR model break down?
-s orbitals are spherically symmetric.
-And the 3 p orbitals are at 90° to each other along the coordinate axis x,y,z.
-Bonding should only be able to happen along these axis… BUT carbon forms bonds at 109°, 120° and 180°…
Explain the orbital hybridisation theory
-This theory aims to correct two issues with atomic orbital theory: number of bonds and molecular geometry
-Considering the carbon atom: by “mixing” the 1 x 2s orbital with the 3 x 2p orbitals we can form sp3 hybridised orbitals.
