modern model of the atom. quantum mechanical model does not describe the movement of the electrons,...
TRANSCRIPT
Modern Model of the Atom
Quantum Mechanical Model
• Does not describe the movement of the electrons, only where they are at any point in time.
• Orbital – a region in which an electron will have the greatest probability of being found. (Any orbital can hold two electrons.)
Quantum Numbers
• Set of 4 numbers describes everything you need to know to find an electron. (Tells its address.)
Principle quantum number (n)
• Tells the distance from the nucleus• The main energy level• Numbers 1-7• Corresponds to rows on the
periodic table
5
Number of Electrons
• The total number of electrons that CAN be held in a principle energy level is
2n2
• Example: The 5th principle energy level can hold 2(52) = 50 e-
Orbital Quantum Number
• s – 1 in a principle energy level
• p – 3 in a principle energy level
Orbital Shapes Continued
• d – 5 in a principle energy level
• f – 7 in a principle energy level
4 of this type 1 of this type
Finding Orbital Quantum #s on the Periodic Table
S Block
D Block
P Block
F Block
Magnetic Quantum Number
• Tells the position in space.
• s – 1 position (2 e- total)
• p– 3 positions (6 e- total)
• d – 5 positions (10 e- total)
• f – 7 positions (14 e- total)
Spin Quantum Number
• Tells the direction of spin.
• Pauli Exclusion Principle: No two electrons can have the same of Quantum Numbers
ORBITAL NOTATIONS AND ELECTRON CONFIGURATIONS
Filling Order
• The “s” shape starts in principle energy level 1.
• p in 2
• d in 3
• f in 4
Filling Order Continued
• The “d” shapes are 1 row lower than they are supposed to be.
• The “f” shapes are 2 rows lower.
Finding Orbital Quantum #s on the Periodic Table
S Block
D Block
P Block
F Block
Orbital Notation
• Shows all four quantum numbers for every electron in the atom.
• A box or line is one orbital.
• An arrow is one electron.
Orbital Notation for Silicon
• Silicon has 14 electrons, so you will draw 14 arrows.
1s 2s2p
3s3p
More Examples:
1s 2s 2p 3s
Magnesium
1s 2s 2p 3s 3p 4s 3d
1s 2s 2p 3s 3p
Copper
Chlorine
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Electron Configurations
• Shorthand versions of orbital notations.
• Does not indicate the magnetic or spin quantum numbers.
• Tells the total number of electrons in each SET of orbitals.
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Writing an Electron Configuration
• Write the electron configuration for Neon.
11s222s222p6
Principle Quantum NumberPrinciple Quantum NumberSubshell
Total Number of Electrons
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Your Turn
• Write the electron configuration for Potassium.
• Write the electron configuration for Copper
• Write the electron configuration for Bromine
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Answers
• Potassium
1s22s22p63s23p64s1
• Copper
1s22s22p63s23p64s23d9
• Bromine
1s22s22p63s23p64s23d104p5
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Excited State Electrons
• You can also draw and recognize elements with electrons in the excited state from an electron configuration.
• For example: What element is shown? 1s22s22p63s13p1
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What did you answer?
• This is NOT Aluminum (Al), this is Magnesium (Mg) in the excited state!!
• Why?
• Look at the 3s sublevel… 1s22s22p63s13p1