electronic structure. electron configuration a description of the electrons in an atom

Electronic Structure

Electron Configuration

•A description of the electrons in

an atom

Orbital•The space in which the electrons (e-) are likely to be found

•Max 2 e- per orbital

Rule of Electron configuration

• Number: energy level (row #)

• Letter: energy sublevel (area)

• Superscript: # of e- in sublevel

• d electrons: 1 level < row #

• f electrons: 2 levels < row #

• Show all filled sublevels

Energy Levels•Corresponds to row #

•1 - 7

•Related to size

Energy Sublevels•Corresponds to an area on the periodic table

•= nodes in orbitals

•s, p, d, f

s - electrons•Columns 1A & 2A

•Spherical orbitals

p - electrons•Col. 3A - 8A or 13 - 18

•Dumbbell shaped orbital

•3 orbitals per sublevel

•1 node

d - electrons•Cols 3B - 2B or 3 - 12

•Transition area (2 nodes)

•Double dumbbell shaped

•5 orbitals in sublevel

f - electrons•Lower removed area

•Triple dumbbell shaped

•7 orbitals per sublevel

•3 nodes

5s -4s -3s -2s -1s -

5p - - -4p - - -3p - - -2p - - -

4d - - - - -3d - - - - -

Ground State•All electrons are in their lowest possible energy state

Excited State•One or more electrons are not in their lowest possible energy state

Degenerate Orbitals

•Orbitals at the same energy level

List, describe, & identify the area of the Periodic Table

for each type of orbital.

Write the ECs for:•Ne

•Rb

•Tc

•As

Write the ECs for:•Si

•Ag

•Br-1

•Fe+2

Write the ECs for:•Zn

•Au

•Al+3

•Fe+3

Electron Dot Diagram•Represents the valence electrons in an atom

•Maximum 4 pairs drawn on an imaginary square around the symbol

Valence Electrons

•Electrons in the outer most energy level

•Electrons involved in chemical reactions

Draw the electron

configuration for Uranium

Octet Rule•8 electrons in the outer level is stable

•elements attempt to get eight electrons in their outer level

Column 1A•1s1, 2s1, 3s1, etc

• Na

Column 2A•1s2, 2s2, 3s2, etc

• Mg

Column 3A• 2s22p1 ,3s23p1, etc

• Al

Column 4A• 2s22p2, 3s23p2, etc

• C

Column 5A• 2s22p3, 3s23p3, etc

• N

Column 6A• 2s22p43s23p4, etc

• O


• Cl


• Ne

EC for Transition El.•4s23d1 4s23d6

•4s23d2 4s23d7

•4s23d3 4s23d8

•4s13d5 4s13d10

•4s23d5 4s23d10

Chromium & Copper Are

Kinky

Transition Dot Diagrams

•Kinky ones have a single

•All the rest have a pair

Inner Transition Dot Diagrams

•All have a pair

HW: Problems 53 – 56 on page 171

Write ECs & EDDs for:

S -16 Cu -29

Sb -51Ca+2 -20

Quantum Numbers

•A more complete description of the electrons in an atom

Quantum Numbersn : Energy level(Row)

l : Energy Sublevel

m or ml : Orientation

s or ms : Spin

Quantum Numbersn : Size

l : Shape or nodes

m or ml : Orientation

s or ms : Spin

Quantum Numbersn : 1 ---> 7

l : 0 ---> (n - 1)

m : - l ---> + l

s : + 1/2 or -1/2

Quantum Numbers•Go from the lowest to highest possibilities:

•Start n with 1, start l with 0, etc.

Quantum Numbers

H: (1,0,0,1/2)

n = 1, l = 0, m = 0, s = 1/2

He: (1,0,0,-1/2)

etc

Drill: Predict EC, QN & EDD for:

•Pb-82

•Gd-64

Give QN, & EDD:Te-52 I-53Fe-26 V-23Pu-94 Al-13Sb-51 Au-79

Oxidation State•The charge or apparent charge of an element

•Oxidation numbers

Negative Ox #• Always = column # - 8

• Exceptions: only in apparent charges: peroxides, hydrocarbons

Positive Ox #• = column #

• = unpaired electrons

• = s e- ---> s + d e-

• Apparent: singles & pairs

Drill:Determine EC, EDD, QN, Ox # of:

Ba-56 Pt-78

Cl-17 Tb-65

Wave Formula•v or c = f •c = speed of light

= wavelength

or f = frequency

Calculate the wavelength of your

favorite radio stationFM in MHzAM in kHz

Plank’s Formula•E = hf = hc/•E = energy

•h = Plank’s Constant

Calculate the energy of a photon from your favorite

radio station:

Calculate the energy of uv

light at 221 nm:

DeBroglie’s Formula

= h/mv

Calculate the wavelength of a 221 g baseball

thrown at 15 m/s:

Calculate the energy and mass of a photon of IR light at 1.326 m:

Spectrum•The unique set of waves absorbed or emitted by a substance

Absorption Spectrum•The unique set of wavelengths absorbed by a substance

•Atomic Absorption Sp

Emission Spectrum•The unique set of wavelengths emitted by a substance

•Atomic Emission Sp

Atomic Absorption Spectrum

•Dark-line Spectrum

Atomic Emission Spectrum

•Bright-line Spectrum

Spectroscopy

•The study of a substance under continuous excitation energy

Determine the electron

configuration (EC) for each of the

following: Mg, Sn, P, K, Cl, & V

Determine the EC for each of the

following: Zr, He, Eu, Cr, U

Determine the EC for each of the

following: Br-1, Kr, & Sr+2

Determine the electron dot diagram (EDD) for each of the following: Mg, Sn, P, K, Cl, & V

Determine the EC & EDD for each of the following: He, Mn,

Eu, Cr, U

Determine the quantum numbers

(QN) for each of the following: He, Mn,

Eu, Cr, U

Determine the EC, EDD, & QN for

each of the following: Mg, Sn,

P, K, Cl, & V

Determine the oxidation state (OS)

for each of the following: Mg, Sn, N,

K, Cl, & V

Determine the EC, EDD, QN, & OS for

elements: 21, 14, 29, & 64

With a UV,visible,IR spectrophotometer waves at 221 nm, 663 nm, & 2.21 m were detected when element X was excited. Calculate the

energy differences among levels 1, 2, 3, & 4.

Excited sodium emits red light at 663 nm.

Determine EC, EDD, QN, OS, & the energy

of the light wave.

Chapter 3 General

•Define all the Key Terms on page 168

Wave Energies

•Work problems:

1 - 10

on page 169

EC

•Work problems:

39 -42

on page 170

Quantum Numbers

•Work problems:

21 - 32

on page 170

electronic structure. electron configuration a description of the electrons in an atom

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