Chemistry - Quantum Mechanics

Front 1

The wave function ψ gives what?

Back 1

It gives the shape of the electronic orbital.

Front 2

What does the wave function ψ2 give?

Back 2

It gives the probability of finding an electron in a given volume of space around the nucleus.

Front 3

A wave function contains three variables, name them.

Back 3

- Principal quantum number "n";
- Sub-shell quantum number "i" which contains s, p ,d and f-orbital; and;
- Orbital quantum number "m".

Front 4

What is Principal quantum number?

Back 4

- "n"
- Same as Bohr's n.
- As "n" becomes larger, the number of allowed orbitals is increased and the size of the orbitals becomes larger together with the atom, the electron is pushed away from the nucleus further.
- Also called shell, n1 first shell n2 2nd shell etc.

Front 5

What is sub-shell quantum number?

Back 5

- Defines the 3d shape of the orbital
- Contains several sub-shells n1, n2, n3 and ,4.

Front 6

What's the equation for sub-shell quantum number?

Back 6

l = n - 1 ;
0, 1, 2, 3, 4...

Front 7

Explain n1. Sub-shell quantum number.

Back 7

n1 contains one sub-shell;
- l = 0, called 1s sub-shell;
- One shape, s.

Front 8

Explain n2. Sub-shell quantum number.

Back 8

n2 contains two sub-shells;
- l = 0, 1, called 2s sub-shell and 2p;
- Shape s & p.

Front 9

Explain n3. Sub-shell quantum number.

Back 9

n3 contains three sub-shells;
- l = 0, 1, 2, called 3s sub-shell, 3p and 3d;
- Shape s, p & d.

Front 10

Explain n4. Sub-shell quantum number.

Back 10

n4 contains four sub-shells;
- l = 0, 1, 2, 3, called 4s sub-shell, 4p, 4d and 4f;
- Shape s, p, d & f.

Front 11

What is orbital quantum number?

Back 11

- it defines the spatial orientation of the orbital with respect to a standard set of coordinated axes.

Front 12

What's the equation for orbital quantum number?

Back 12

- l x ± 1
- l1 x ± 1 = -1, 0, 1 e.g.
- l2 x ± 1 = -2, -1, 0, 1, 2 e.g.

Front 13

What's m when l is 0?

Back 13

ml = 0, 1s orbital, spatial orientation.

Front 14

What's m when l is 1?

Back 14

ml = -1, 0, +1 3p orbital, three spatial orientation.

Front 15

What's m when l is 2?

Back 15

ml = -2, -1, 0, +1, +2 5d orbital, five spatial orientation.

Front 16

What's m when l is 3?

Back 16

ml = -3, -2, -1, 0, +1, +2, 3 7f orbital, seven spatial orientation.

Front 17

What's another name for orbital quantum number?

Back 17

Magnetic quantum numer.

Front 18

What's another name for sub-shell quantum number?

Back 18

- Angular momentum quantum;
- Azimuthal quantum number.

Front 19

There is a forth quantum number, what is it called?

Back 19

It's called spin quantum number (ms).

Front 20

Describe Spin quantum number.

Back 20

- Explains how the electron can spin, eighter counter or clockwise.
- No two electrons in an atom and orbital can have the same four quantum numbers, if n, l and m are the same then ms should be different.

Front 21

What's the Pauli exclusion principle?

Back 21

Describes how the spin quantum number works.
- He discovered it in 1926.

Front 22

Describe the S-orbital.

Back 22

- All S orbital are spherical;
- As n increases the s-orbital gets longer and the number of nodes increase.
- nr of nodes = n-1

Front 23

What's a node?

Back 23

It's a region in space where the probability of finding an electron is 0.
- At a node ψ2 = 0

Front 24

Describe the p-orbital.

Back 24

- There are three p-orbitals px, py & pz. These lie along the x-, y- & z-axes of the cartesian system. These correspond to the allowed values of ml (-1,0,+1 eg)
- As n increases the p-orbital gts larger.
- All p-orbitals have node plane at the nucleus.

Front 25

What shape do p-orbitals have?

Back 25

Dumbbell shape.

Front 26

Describe d- and f-orbital

Back 26

- There are 5 d-orbitals;
-3/5 d-orbitals lie in a plane bisecting the x-, y- & z-axe;
-2/5 d-orbitals lie in a plane alinged a long the xyz axe;
-4/5 d-orbitals have four loves each in clover leaf shape.
One d-orbital has two loves and a collar.

Front 27

Orbitals of the same energy are said to be?

Back 27

Degenerate.

Front 28

When do the S- and p-orbital stop being degenerate?

Back 28

For n≥2 because the electron interact with each other.

Front 29

What does electron configuration do?

Back 29

- It tells us which orbital the electron for an element is located;
- Electrons fill orbitals starting with the lowest n energy orbital and move to higher orbitals;
- Paulis principle;
- Hund's rule.

Front 30

What's Hund's rule?

Back 30

It states that degenerate orbitals, orbitals with the same energy levels have electrons filling up each orbital singly before any orbital gets a second electron.