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Entry Task: October 16 th -17 th Block 1. Question: What is the shape of the p orbitals? How many electrons can a filled p orbital fill? You have 5 minutes!. Agenda. Sign off and discuss section 5-2 Notes on Electron configuration H.W. Section 5-3 ws. Break out periodic Table!!.
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Entry Task: October 16th -17th Block 1 • Question: What is the shape of the p orbitals? How many electrons can a filled p orbital fill? • You have 5 minutes!
Agenda Sign off and discuss section 5-2 Notes on Electron configuration H.W. Section 5-3 ws
Break out periodic Table!!
s= 2 electrons 1s 1s p= 6 electrons 2p 2s 3p 3s d= 10 electrons 4s 4p 3d 4d 5p 5s 6s 6p 5d 7s 6d f= 14 electrons 4f 5f
I can… • Apply the rules to fill in an electron diagram • Write electron configuration for a given element.
How do electrons fill the atomic orbitals? There are rules when filling the atoms orbits with electrons.
#1 Aufbau Principle: each electron occupies the lowest energy orbital available. You fill in order of increasing energy. s p d f Different sublevels have different energy levels. All orbitals in a sublevel have equal energy p > s 2px = 2py = 2pz
#2 Pauli Exclusion Principle • A maximum of 2 electrons are allowed in a single atomic orbital, but only if they have opposite spins!
#3 Hund’s Rule • Fill each sublevel (i.e. all p-orbitals) with single electrons with parallel spins first. Then come back to put 2nd electrons in. First: 2p Think of it as the school bus rule. Fill up the seats singly first then double.
Aufbau Diagram s= 2 electrons p= 6 electrons d= 10 electrons f= 14 electrons
Aufbau Diagram Hydrogen
Aufbau Diagram What rule applies here? Pauli Exclusion- 2 different spins Helium
Aufbau Diagram Lithium
Aufbau Diagram What rule applies here? Aufbau Principle- Fill lower energy levels first Beryllium
Aufbau Diagram Boron
Aufbau Diagram What rule applies here? Hund’s Rule Fill the sublevel first Carbon
Aufbau Diagram Nitrogen
Notations of Electron Configurations • Standard • Shorthand
Aufbau Diagram Fluorine 2p5 2s2 1s22s22p5 1s2
Standard Notation of Fluorine Number of electrons in the sub level 2,2,5 1s22s22p5 Main Energy Level Numbers 1, 2, 2 Sublevels
Shorthand Notation • Use the last noble gas that is located in the periodic table right before the element. • Write the symbol of the noble gas in brackets. • Write the remaining configuration after the brackets. • Ex: Fluorine: [He] 2s2 2p5
START with Hydrogen= put its Electron configuration in its square H 1s1
Lithium= put its Electron configuration in its square Li 1s22s1
Neon= put its Electron configuration in its square Ne 1s22s22p6
Sodium= put its Electron configuration in its square- Noticed I put it into shorthand Na [Ne]3s1
What’s wrong with this configuration? 1s22s22p63p63s2 Correct: 1s22s22p63s23p6 s orbitals are lower energy than p orbitals.
Aufbau Diagram 20 electron Chromium 24 Cr [Ar]4s13d5
Aufbau Diagram 20 electron Copper 29 Cu [Ar]4s13d10
Exceptions to the rules! Cr [Ar]4s13d5 Cu [Ar]4s13d10 WHY?These electron configurations are more stable for the elements!
http://www.chempractice.com/drills/java_AO.php Aufbau Diagram http://www.lon-capa.org/~mmp/period/electron.htm