Quantum Mechanics Flashcards
Unit 1 Review
What did Schrödinger develop?
A model that described electrons that r bound to
nucleus as a standing wave
A circular wave can only have ________ fit into wave lengths.
Whole numbers
Schrödinger developed a
mathematical equation that could?
Calculate energy the
level of the electron
Define the orbital around the nucleus
What is the Quantum mechanical model?
Application of quantum theory & wave behaviour to explain the properties of electrons in atoms:
- Schrodinger’s wave equation
- Heisenberg’s uncertainty principle
What is an Orbital?
The region around the
nucleus where an electron
has a high probability of being found.
What is Schrödinger’s wave equation?
Math equation that could be used to calculate energy level of the electron & define the orbital around the nucleus.
What is Heisenberg’s uncertainty principle?
It’s impossible to know both the exact position and speed of an electron at a given time.
Best we can do is describe the probability of finding an electron in a specific location.
What are the 4 Quantum Numbers?
- Principal (n)
- Secondary (I)
- Magnetic (m1)
- Spin (m2)
What it the meaning of Principal Quantum Number?
- Describes size & energy of an atomic number
- Defines 7 energy levels
What it the meaning of Secondary Quantum Number?
- Describes shape of & energy of an orbital
- Has only whole #’s
ex, n=3, “ I “can have values of 0,1,2 (n -1)
What it the meaning of Magnetic Quantum Number?
Describes the orientation of an orbital
Ex. n=3
I = 0,1,2 ->
M(I) = -2,-1,0, +1, +2
What it the meaning of Spin Quantum Number?
The spin of an electron, either clockwise and counter clockwise
Has value of +1/2 & - 1/2
Describe “ S “ orbitals
Value “ I “ = 0
Spheric Shape
Holds 2 electrons
Describe “ P “ orbitals
Value “ I “ = 1
Shape = figure eight
Holds 6 electrons
Has 3 different shapes
Describe “ D “ orbitals
Value “ I “ = 2
Has 5 shapes
Can hold 10 electrons
Describe “ F “ orbitals
Value “ I “ = 3
Has 7 shapes
Can hold 14 electrons
What is Pauli’s exclusion principle
In a atom, no 2 electrons can have the same set of 4 quantum numbers
What is Aufbau principle?
Electrons fill orbitals at the lowest available
energy orbital before filling higher energy orbitals.
What is Hund’s rule?
The lowest energy configuration, within orbitals of the same energy, is the one with the max number of unpaired electrons.
The 2 types of electron pairs?
Bonding electron pairs (covalent bonds)
and Lone electron pairs (don’t participate in chemical bonds)
What is the VSEPR theory?
Method to predict the 3D
structure around an atom by minimizing the
repulsive force between electron pairs.
What is a sigma bond?
type of bond that forms when the lobes of
two orbitals directly overlap.
When s/p and/or hybrid orbitals overlap
What is a Pi bond ?
Type of bond that forms when the lobes of two
parallel orbitals overlap side by side.
Pi bonds are used to form what type of bonds between atoms?
Used to form double & triple bonds
What does a double bond contain?
Contains 1 sigma bond
and 1 pi bond
What does a triple bond contain?
Contains 1 sigma bond
and 2 pi bonds
