Quantum model

Quantum model

Electron Configuration

Quantum principles

Quantum Model vsBohr's model

Orbitals shapes

BOHR configuration + Valence electrons

Quantum model vs Bohr's model

BOHR's MODEL

QUANTUM MODEL

(shells)

• “Planetary" model
• Electrons travel in 7 circular ORBITS
• with increasing energy levels:
• (7 energy "shells")

• “Electron CLOUD" model
• Energy levels have sublevels (sub- shells)
• called ORBITALS (s p d f )

• Orbitals have different shapes

Quantum model vs Bohr's model

BOHR's MODEL

QUANTUM MODEL

(shells)

• “ORBITALS" (s p d f ) with different shapes)
• sub- levels within Bohr's energy shells

• 7 circular ORBITS (K,L,M,N,O,P,Q)
• = energy shells

Quantum model vs Bohr's model

BOHR's MODEL

QUANTUM MODEL

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• ORBITALS (s p d f ) = sub- levels within the energy shells

• 7 circular ORBITS = 7 energy shells

Main principles behind the model

3. Schrödinger's wave function equation -which describes the SHAPE of the ORBITALS: Orbitals: are high PROBABILITY REGIONS where electrons can be located in an atom. - Quantum numbers- are derived from this equation

1. Wave-Particle duality (DeBroglie)Electrons behave both like particles and waves

2. Heisenberg uncertainty principle:It’s impossible to know an electron’s exact position and momentum (speed +force) at the same time

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Orbital Shapes

Orbital: a region with a high probability of finding electrons

Orbital Shapes and orientation

s+p together

s orbital

s+p+d together

Each SUB-orbital can fit max 2e-

How many TOTAL electrons can each orbital contain??

s = 2e-

p = 6e-

d = 10e-

f = 14e-

All orbitals together...

Can we easily draw these orbitals???

Electron Configuration

• It is the arrangement of the electrons in an atom into ORBITALS

• it is the way to describe the probable DISTRIBUTION of electrons in the energy levels and sub-levels (orbitals):

Outer orbitals can OVERLAP with lower energy levels

Therefore, the order is not totally numerical:

Steps to follow:

Find out the number of electrons (e-)

1)

Follow the Madelung rule/ Aufbau diagram

2)

• Aufbau diagram- indicates the correct order to fill in the orbitals in the electron configuration

• "electrons always occupy the LOWEST available ENERGY sublevel"

s p d f

Madelung rule / Aufbau diagram

< Start here

Follow the arrows to find the correct order

Example-1

s p d f

How many electrons does this atom have?

since it's NEUTRAL, it has 5 electrons

Example-1

s p d f

How many electrons does this element/atom have?

Example-2:

http://youtu.be/TjVrcw2sZLs

Exercises

https://docs.google.com/spreadsheets/d/1wCC9Dn_er7ORnXIHAm8Hjf7QnolBKdWsVo7xcHHl1sI/edit?usp=sharing

BOHR Configurationfrom Electron Configuration

Bohr Configuration is built using the Electron Configuration

28-Ni-59

1st shell: 2e-2nd shell: 8e- 3rd shell: 16e- (2+6+8) 4th shell: 2e-

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁸

28 e-:

Energy level/shell

28 p+ 31 N

2e-

8e-

16e-

2e-

2, 8, 16, 2

Bohr diagram

Bohr Configuration:

Valence Electrons

Valence electrons are the electrons located on the outermost energy shell of an element

They are responsible for the CHEMICAL REACTIVITY of the element (bonding abilities)

How many VALENCE electrons does Nickel have??

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁸

28 p+ 31 N

2e-

8e-

16e-

2e-

2, 8, 16, 2

Bohr diagram

Bohr Configuration:

Exercises:

1) What is the Atomic Number of an element with the following electron configuration?

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁸

2) How many PROTONS in an element with the following Bohr configuration? 2,8,18,2

for IONS:

3) Which element has the following electron configuration AFTER REMOVING 1e-?

1s² 2s² 2p⁶ 3s² 3p⁶ 18+1= 19e K

z=19 a=35 (+1) e-? 18e- 1s2 2s2 2p6 3s2 3p6 z=28 a= 58 (-2) e-? 30e- 1s2 2s2 2p6 3s2 3p6 4s2 3d10

TC: Terminal Configuration

What is the Electron Configuration for Nickel? (Z=28)

28-Ni-59: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁸