Quantum Numbers
The uncertainty principle is based off of inversely proportional relationship between momentum and position. What does this mean?
The more accurately you know the position of the variable, the less accurately you know the momentum of the variable. The reverse is also true!
Pauli Exclusion Principle
The rule that an orbital can hold only two electrons with opposite spin
What are the values that represent the azimuthal quantum number (l)?
l= 0, 1, 2, 3.... n - 1 l = angular momentum
What are the values that represent the Magnetic Quantium Number(ml)?
ml = -l to +l The values for ml depend on l
What values represent the spin quantum number (ms)?
ms = +1/2 AKA up ↑ ms = -1/2 AKA down ↓
The principle quantum number (n) indicates what property of an electron?
n = 1, 2, 3..... Indicates the main energy level, shell
Quantum numbers
n, l, ml, ms
The total number of total orbitals within any shell level (n) can be found with the formula ____________
n^2 example for n1 aka 1^1 = 1 there is only one orbital, the s orbital for n^2 aka 2^2 = 4 there are 4 orbitals
l = 1
p orbital
l = 0
s orbital
Hund's rule
when an electron is added to a subshell, it will always occupy an empty orbital if one is available
Draw out the Heinsenburg uncertainty equation
∆x = uncertainty in position ∆p = uncertainty in momentum MUST BE GREATER THAN OR EQUAL TO h= Planck's Constant 6.6260 × 10-34 m2 kg / s /4π
Draw out the equation for the Balmer series
1/λ = R (1/i^2 - 1/j^2) R = Rhydberg constant (1.097x10^7) Lower energy level^2 - Higher energy level ^2
How many nanometers are in a meter?
10^9
Max number of electrons in a shell formula
2n^2
What does an inversely proportional relationship mean?
A relationship between two variables in which the product is a constant. When one variable increases the other decreases in proportion so that the product is unchanged.
What does the magnetic quantum number represent?
Indicates the orientation of an orbital around the nucleus
The angular momentum quantum number (l) indicates what property of an electron?
Indicates the shape of the orbital
Pauli Exclusion Principle, how to remember
No atom has the same 4 quantum numbers. All other addresses are EXCLUDED!!
paramagnetic vs diamagnetic
Paramagnetic, have unpaired electrons(single) and are attracted to magnetic fields Diamagnetic, have paired electrons (married) and are slightly repelled by a magnetic field (repelled from other attractions because they are married)
Quantum #s mapped out on the periodic table
Principle quantum # is found on the left!
What is the Balmer series?
The Balmer series is the name given to a series of spectral emission lines of the hydrogen atom that result from electron transitions from higher levels down to the energy level with principal quantum number 2.
Which principle states you can not know the position and momentum of a particle accurately at the exact same time.
Heisenberg uncertainty principle
l = 3
f orbital
l = 4
g orbital
As the principle quantum number increases, the average ____________ from the nucleus increases, as well as the _________________ a) energy, distance b) space, kinetic energy c) potential energy, kinetic energy d) distance, energy
d) distance, energy As the principle quantum number increases, the average DISTANCE from the nucleus increases, as well as the ENERGY
Using the n + 1 rule, which will fill first? The 5d subshell or the 6s subshell?
For 5d, n = 5 & l = 2, so n+l = 7 For 6s, n = 6 & l = 0, so n+l = 6 The 6s subshell has lower energy and will fill first
What is the h bar constant? ħ
H bar constant is equal to the Planck constant divided by 2π, and is denoted ħ (pronounced "h-bar"):
An electron is travelling along the x-axis with a uniform velocity of 2x10^6 m/s. If the velocity has been calculated to a precision of 0.15%, calculate the maximum accuracy with which the position of the electron could be measured at the same instant in time. Assume Me (mass of electron) = 9.11x10^-31 ħ = 1.055x10^-34
Apply the Heisenberg uncertainty principle! (∆x)(∆p) ≥ ħ ∴ ∆x ≥ ħ / ∆p Answer 38.6 nm https://youtu.be/RJxdSk8X6dg?list=PLdonEKZrk3DmUM3WLPN5HPqCRhyi1y52P
Aufbau Principle, how to remember
Aufbau sounds like off-center, and the diagram depicts an off center. Also, lower energy orbitals will bau (bow) to higher energy orbitals Diagram depicts direction of increasing n + l value
Write out the noble gas configuration for Cr and Cu
Cr = [Ar]4s1 3d5 Cu = [Ar]4s1 3d10 https://www.youtube.com/watch?v=sLgI7jRf4rM
Hund's Rule, how to remember
Electrons fill orbitals one at a time before doubling up! Think of how awkward it would be if someone sat next to you on an empty bus and said "hey hun"
Aufbau Principle
Electrons must occupy the orbitals of lowest energy first ; also known as the 'Building-Up Rule'
Write out the electron configuration for Fe3+
[Ar] 3d5 pg.24 gen chemistry OR https://www.youtube.com/watch?v=YYnu-9lud-E
Draw out the noble gas notation for Na
[Ne] 3S1
l = 2
d orbital
