Name:______________________________________________________________________________
Electron Configurations Notes (Unit 3.7 and 3.8)
ORBITALS
•
•
•
•
Region outside the nucleus where the electron has the highest probability of being.
Drawn with a fuzzy border like the atmosphere around earth.
No defined border because there is a small chance the electron may be outside this
region.
The orbital pictured to the right is the 1s orbital. It is the lowest energy level for
hydrogen.
PRINCIPAL ENERGY LEVELS
• Remember Bohr demonstrated that hydrogen had 4 __________ energy
levels.
• These energy levels are called ________________ energy levels.
• Each principal energy level can be divided into ________________.
• The first energy level has _________ sub energy level.
• This sub energy level is known as the _______ orbital.
• The 1 stands for the principal energy level and the s stands for its shape (spherical)
• The 1s orbital can hold ______ electrons.
• Remember the first ___________ of the “Hog Hilton” had one room that could hold two
pigs.
• ___________ total electrons in the 1st principal energy level.
PRINCIPAL ENERGY LEVEL 2
•
•
•
•
•
The second energy level has ______ sub energy levels. 2s and 2p
The 2s orbital is just like the 1s orbital but ____________ in size.
The 2p sublevel consists of _____ orbitals.
Each of the ______ orbitals holds two electrons for a total of 6.
_____________ total electrons in the 2nd principal energy level.
2P ORBITALS
• The three 2p orbitals are “_________” shaped.
• The x, y, and z tell which _____________ the lobes are parallel to.
PRINCIPAL ENERGY LEVEL 3
• The 3rd energy level has _________________ sublevels: 3s, 3p and 3d.
• The 3s orbital is shaped like the 1s and 2s; it is just larger and _____________ from the nucleus.
• The 3 p sublevel also has 3 orbitals. (3px, 3py, and 3pz) They are shaped like the 2p orbitals only larger.
• The 3d sublevel has _____ orbitals. Each orbital can hold 2 electrons for a total of ______electrons
• _______________ total electrons in the 3rd principal energy level.
Name:______________________________________________________________________________
PRINCIPAL ENERGY LEVEL 4
• The 4th energy level has ___________ sublevels: 4s, 4p, 4d and 4f.
• There is one 4s orbital, three 4p orbitals, five 4d orbitals just like the 3s, 3p and 3d orbitals except they are
__________.
• The 4f sublevel has ______ orbitals. Each orbital can hold 2 electrons for a total of _____ electrons.
• ______________ total electrons in the 4th principal energy level.
ELECTRON ARRANGEMENTS
• The most attractive orbital to an electron in an atom is always the ______, because this orbital is ____________
to the nucleus.
• Hydrogen has 1 electron in this orbital so its electron configuration is: 1s1
• Helium has 2 electrons in this orbital so its electron configuration is: __________
• Elements with more than two electrons fill the 1s orbital first ___________ filling higher energy orbitals.
• The 1s orbital gets filled first, then the 2s, then the 2p, then the _______ followed by the _______.
• Since lithium has 3 electrons, two can fit in the 1s orbital and the last goes in the _____ orbital.
• Therefore the electron configuration for lithium is: ______________________
NOBLE GAS NOTATION
• Example 1: Write the electron configuration for Sulfur & Neon
• S (16 electrons): ___________________________
• Ne (10 electrons):__________________________
• Instead of writing out the full electron configuration for sulfur use the NOBEL GAS notation: ________________
• Example 2: Write the regular electron configuration for boron and helium:
• B (5 electrons): ________________________________
• He (2 electrons):_______________________________
• Now write the noble gas notation for Boron:_______________________________
ORBITAL DIAGRAMS
• Orbital diagrams show all of the ________________ in an atom.
• They are similar to the Hog Hilton drawings you made.
• Just like the hogs in the Hog Hilton two electrons can fit in each orbital but they must be ______________ in
opposite directions.
• We represent this on an orbital diagram as an up and a down _____________.
• Electrons spread out as _________ as possible before pairing (because of repulsion).
• This is known as _____________ Rule or the “Empty _______ Seat Rule”
• If there are 4 electrons in the p-orbital:
ORBITAL FILLING ORDER
• What is the electron configuration for Potassium?________________________
• It is actually:____________________________
• We fill up the 4s orbital before filling up the 3d orbitals.
• Why?
▫ Because the d and f orbitals require a lot of ____________to fill.
Name:______________________________________________________________________________
•
•
•
•
•
•
•
Remember the periodic table you colored with the s, p, d and f blocks?
We could’ve used it to guess what the last orbital for potassium would be based on its ____________ in the
periodic table.
It is in the s-block.
It is in the first column of the block
It is in the fourth period.
The diagram below shows the ____________ in which the orbitals get filled.
Notice that the ___________ energy level starts to get filled before the ____________ energy level is completely
filled.
VALANCE ELECTRONS
• The definition hasn’t changed!
• Still the number of electrons in the highest energy level.
• Example: Potassium-____________________________
Number of Valance electrons_______________
• Write the electron configuration for Gallium & identify the VALENCE electrons!
• Gallium (31 Electrons): ______________________________
• Gallium has ___ total valance electrons!
• This makes sense because it is in group _______!
PERIODIC TABLE PATTERNS
•
Example 1: Strontium: ____________________
•
Example 2: Germanium:________________________________
•
The “A” column numbers= number of total
_______________ electrons.
•
The ____________ number= energy level
(subtract for d and f)
•
Column number ______ a block = number
of electrons in that orbital.
Name:______________________________________________________________________________
Energy Levels Diagram
Directions: Label each energy level and each sub level.