The Bohr Model meets the Quantum Mechanical Model
The Quantum Mechanical
Model adds details to the
Bohr Model.
It identifies ____________,
which are s, p, d, and f, on
each energy level.
Sublevels are composed of
___________________,
which can hold ____
electrons.
,
vs.
Why does a hamburger have
lower energy than a steak?
The farther away an electron is from the nucleus, the
higher the energy it has. An electron in its normal energy
level is in its ground state.
Because it’s in the ground state!
Rules governing ground state locations of electrons and “Do” and “Don’t”:
Pauli Exclusion Principle: each
Hund’s Rule: you must place one
Aufbau Principle: electrons fill the
orbital can hold TWO electrons with
opposite spins.
electron in each orbital before pairing
them. This rule is often called the
“Empty Bus Seat Rule.”
lowest energy orbitals first. This rule is
often called the “Lazy Tenant Rule.”
Do this
Do this
Do this
Not this
Not this
Not this
Expressing Electron Configuration in Different Notations:
These are two of the ways to write out an electron configuration for an atom. The Orbital Diagram Notation
shows all energy levels, sublevels, and orbitals, and how the electrons are arranged in them. Suppose you have
oxygen with 8 electrons. The following shows how each orbital is filled with the appropriate number of electrons:
Orbital Diagram Notation for Oxygen
1s
2s
2p
Standard or Shorthand Electron Configuration Notation writes out the energy levels and sublevels of the
electrons, stating the number of electrons in each location as a superscript in order of increasing energy.
Suppose you have oxygen with 8 electrons. The following shows the standard/shorthand electron configuration notation:
Shorthand or Standard Electron Configuration Notation for Oxygen
1s22s22p4
Example. Atomic Number: __11__ Element: ___Sodium______________ Symbol: ___Na_____
Orbital Diagram of Electron Configuration:
Shorthand Electron Configuration Notation:
1s22s22p63s1
↑↓
↑↓
↑↓ ↑↓ ↑↓
↑
1s
2s
2p
3s
Whole Class Practice. Atomic Number: __28__ Element: ________ ______________ Symbol: _________
Orbital Diagram of Electron Configuration:
Shorthand Electron Configuration Notation:
1s
2s
2p
Electron Configuration Practice
Please write the correct standard electron configuration and noble gas configuration for each of the following elements.
Element
1.
Aluminum
2.
Argon
3.
Carbon
4.
Magnesium
5.
Nickel
6.
Bromine
Orbital Diagram Electron Configuration
Standard/shorthand Electron
Configuration