Schrodinger wave equation / quantum no.s / orbitals Flashcards
What is the mathematical function which describes an e- as a wave within a region of space?
Ψ (wavefunction).
What does Ψ represent in schrodinger’s wave equation?
It is a mathematical function ( a wavefunction) which describes an e- as a wave within a region of space.
What does Ψ2 represent in schrodinger’s wave equation and what does this mean?
The probability of finding an e- at a given region.
Since the wavefunction is squared, it means that the probability will always be zero or positive.
What does 95%+ probability mean in terms of e-s?
If the probability is 95%+, then it is very likely that an e- will be found in this region.
This region is called an atomic orbital.
Define an atomic orbital in terms of probability using schrodinger wave equation.
An atomic orbital is a region defined by a probability of 95%+, where it is very likely that an e- will be found.
What is a quantum number?
It uniquely identifies / labels each inidividual electron in an atomic orbital of any atom.
How can an individual electron be identified within an atomic orbital in any atom?
Use a series of quantum numbers.
E.g. 1s2
What does the schrodinger wave equation or quantum numbers try to achieve?
It tries to find and uniquely label / identify each electron in atomic orbital of any atom.
Practical attempt on theory at actually finding an e- in a given space.
What are the four different types of atomic orbitals?
s, p, d, f
Total number of electrons held in each type of orbital?
s = 2
p = 6
d = 10
f = 14
What are the sub orbitals in p-orbital?
px = 2 e-s each
py = 2 e-s each
pz = 2 e-s each
How many e-s can be held in a sub-orbital and what type of e-s?
2 e-s with opposite spins.
What is the shape of an s orbital?
spherically symmetric
What is the shape of p orbitals?
p orbitals are aligned mutually perpendicular along axes x, y and z
What does electronic configuration of an atom mean?
Filling up of orbitals with electrons in an atom.
What is the order of energy of orbitals starting from shell no. 1 to 4?
1s > 2s > 2p >3s > 3p > 4s > 3d > 4p
How many s, p, d and f orbitals are there?
s orbital = 1
p orbital = 3
d orbital = 5
f orbital = 7
Why is 4s orbital filled before 3d?
Bc 4s orbital has lower energy than 3d therefore it is filled up first.
What are the three rules when filling up available atomic orbitals with electrons (electronic configuration)?
- Pauli exclusion principle = each e- in an atom has an unique set of 4 quantum numbers.
- The aufbau “building” principle = lowest energy orbital is filled first then next lowest e.g. 1s then 2s
- Hund’s rule = when filling a set of degenerate orbitals , FIRST fill in each orbital with single electrons until ALL denegerate orbitals have one e- with parallel spins.
THEN pair up e-s with opposite spins in each degenerate orbital.
What is a degenerate orbital?
Orbitals with equal energy.
Incorrect use of Hund’s rule example.
1s2, 2s2, 2px2, 2py1
Nitrogen = 7 electrons.
Show its electronic configuration with only Aufbau principle.
1s2, 2s2, 2p3
Nitrogen = 7 electrons.
Show its electronic configuration with both Aufbau principle and Hund’s rule.
1s2, 2s2, 2px1, 2py1, 2pz1
Explain the pauli exclusion principle and what is it used for?
Used in electronic configuration i.e. filling up available atomic orbitals with e-s.
Each e- in an atom has an unique set of 4 quantum numbers.
