Chemistry 4.5 Electron Configuration

Electron configuration chart

2 6 10 14 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 5f 6s 6p 6d 7s 7p

Arrows in an orbital diagram?

Direction the electron spins, each arrow represents an electron Upward-- counterclockwise Downward-- clockwise Based on magnetic properties of spinning electron

What is electron configuration determined by?

Distributing the atom's electrons among levels, sublevels, and orbitals based on a set of stated principles

Electron configuration

Distribution of electrons among the orbitals of an atom

Paul Exclusion Principle

An orbital can hold a maximum of 2 electrons that spin in opposite directions Electrons with opposite spins occupy orbital they are said to be paired Single electron in an orbital is unpaired

Exceptions to Aufbau Principle

Chromium and copper Due to subtle electron-electron interaction in orbitals with very similar energies

What does color of light emitted by an element as it goes from an excited state to ground state depend upon?

Color emitted by an element depends on the energy gap between its sublevels

Hund's Rule

Electrons occupy equal-energy orbitals so that a maximum number of unpaired electrons results Electrons are first placed into orbitals one by one until all orbitals have 1 electron, then you would place the next electrons to pair up with the existing electrons

Most stable state of the atom

Ground state Lowest energy state of the atom Way atoms normally exist

Orbital diagram

Horizontal diagrams that illustrates the way electrons populate orbitals

Aufbau Principle

In the ground state of an atom, electrons are added one at a time to the lowest energy orbitals available until all the electrons of the atom have been accounted for "Aufbau" German for "building up"

When electrons populate which orbital is the atom said to be in ground state?

Lowest energy orbital

How do you determine number of boxes for orbital diagram?

Use s p d f s = 1 p = 3 d = 5 f = 7

How do you determine the number of unpaired electrons?

Using the orbital diagram, determine how many boxes have only a single arrow (electron), and how many there are is how many unpaired electrons there are If a box is empty, then it is not paired or unpaired -- neither so do not count

How do you determine the valence electrons?

Using the written out electron configuration, find the highest coefficient and add the subscript electrons of the highest coefficient

What does electron configuration describe?

Where the electrons are found and what energies they possess