Electrons Flashcards
States that no two electrons can occupy the same exact energy level or have the same set of four quantum numbers
Pauli Exclusion Principle
Describes the location and shape taken by each electron cloud in an atom.
Schrödinger’s equation
Three ways to model the location of electrons in atoms
Quantum numbers, orbital notation, and electron configurations
Quantum numbers
Describe the general distance from the nucleus, the type of orbital field, the orientation of that orbital, and the ‘spin’ direction of each electron in each orbital.
Orbital notation
Identifies where each electron exists in each orbital. In this model, it is clear whether or not electrons have parallel spin.
Electrona configurations
Identify the number of electrons in each type of orbital at each energy level.
Aufbau Principle
Electrons exist first at the lowest possible energy level, unless energy has put them into an exited state.
Hund’s Rule
States that electrons enter orbitals of equal energy singly, with the same spin (ie. unpaired), before they become paired.
Principle quantum number: n
n: represents the shell an electron occupies
Shells are also called energy levels.
Shells can have possible values of n= 1,2…7.
This value indicates the approximate distance to the nucleus and relative energy. Electrons with higher values of n are farther from the nucleus and have higher energy.
Angular momentum quantum number: l
l: represents the subshell the electron occupies.
This number describes the shape of an electron’s orbital. Possible shapes include:
When n=1, 1=0(meaning there is one possible type of orbital, s)
When n=2, 1=0(s orbital) or l=1(p orbital)
When n=3, 1=0(s orbital), l=1(p orbital), or l=2(d orbital)
When n > or =4, 1=0(s orbital), l=1(p orbital), l=2 (d orbital), or l=3(f orbital)
Magnetic quantum number: m(sub l)
Represents the orbital position.
The orbital with the most negative number is filled first.
Possible values range from -1…0…1 for all possible values of n.
When 1=0 m(l)=0 (there is one value, representing one possible s orbital)
When 1=1, m(l)=-1,0,1(there are three possible d orbitals)
When 1=2, m(l)=-2,-1,0,1,2(there are five possible d orbitals)
When 1=3, m(l)=-3,-2,-1,0,1,2,3(there are seven possible f orbitals)
Magnetic spin quantum number: m(sub s)
Each orbital can contain as many as two electrons, one with a positive spin (+1/2) and one with a negative spin (-1/2).
The first ground state electron in each orbital takes the +1/2 value.
Diamagnetism
Diamagnetic elements have paired electrons in each orbital. To have this situation, all subshells are filled. These elements are not affected by magnetic fields.
Paramagnetism
Paramagnetic elements have an unpaired electron in at least one orbital. The unpaired electron creates a magnetic field in the atom that responds to external magnetic fields.
Molecular orbitals
Create diamagnetism and paramagnetism
