





















Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community for help and clear up your study doubts
Discover the best universities in your country according to Docsity users
Free resources
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
The arrangement of electrons in an atom is its electron configuration. • It is impossible to know where an electron is or how fast it is traveling at any given ...
Typology: Schemes and Mind Maps
1 / 29
This page cannot be seen from the preview
Don't miss anything!
complicated than planets orbiting the Sun.
For example: 1s is an s shaped orbital on the 1 st energy level, which is closest to the nucleus
Who figured this out and how does it relate to the apartment analogy?!? Apartment House Rules Electron Rules From the Bottom Up : Rooms must be filled from the ground floor up. Fill the one room on the first floor before starting to put new tenants on the second floor. Then fill the s room before the p rooms. At higher floors the order might change a bit.
Aufbau Principle : the electrons fill the available orbitals from lowest energy to highest energy. In the ground state all the electrons are in the lowest possible energy level.
Singles First : the owner of the building wants to have the tenants spread out as much as possible. For that reason singles are placed in rooms before couples. If couples must be placed into a room then all of the other rooms on that floor must already have a single in them.
Hund’s Rule: The electrons must be placed into the orbitals in such a way that no pairs are put together unless absolutely necessary. That is, single electrons must be placed into boxes first and then paired up if necessary.
Opposite “Gender” Only : When two people are placed in a room they must be of opposite genders. No men may room together and no women may room together. This is an arbitrary rule on the part of the owners: in a just world we wouldn’t have to follow it. But quantum mechanics has nothing to do with justice.
Pauli Exclusion Principle : Electrons come in two varieties based on the direction they are ‘spinning’. There is an Up spin and a Down spin. Up and Down spins are always paired together and Up-Up or Down-Down combinations are not allowed. No two electrons can ever be in the same place at the same time.
The Periodic Table – A Cheat Sheet for Knowing the Order of Filling Electron Orbitals
1 (^23) 4 5 6 7
1s^2 2s^2 2p^6 3s^2 3p 2
Notice that when you get to the 3d orbital, it is higher in energy than the 4s orbital. The rule is that electrons fill lower energy orbitals first, so electrons will actually fill the 4s orbital after 3p, then electrons will begin to fill the 3d orbital.
[Ne]3s^2 3p^5
[He]2s^2