E LECTRON C ONFIGURATIONS Niels Bohr The way electrons are
arranged around the nucleus. 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p
6 5s 2 4d 10 4p 6 5s 2 4d 10 5p 6 6s 2 4f 14 5d 10 6p 6 Chapter 12,
page 364
Slide 3
Energy Levels and Sublevels The emission spectrum for each
element has a characteristic set of spectral lines. This means that
the energy levels within the atom must also be characteristic of
each element. When scientists investigated multi-electron atoms,
they found that their spectra were far more complex than would be
anticipated by the simple set of energy levels predicted for
hydrogen. These spectra have many more lines than the spectrum of
hydrogen.
Slide 4
Some lines are grouped close together, and there are big gaps
between these groups of lines. Energy Levels and Sublevels The big
gaps correspond to the energy released when an electron jumps from
one energy level to another. This suggests that sublevelsdivisions
within a levelexist within a given energy level. The interpretation
of the closely spaced lines is that they represent the movement of
electrons from levels that are not very different in energy.
Slide 5
If electrons are distributed over one or more sublevels within
an energy level, then these electrons would have only slightly
different energies. The energy sublevels are designated as s, p, d,
or f. Energy Levels and Sublevels Each energy level has a specific
number of sublevels, which is the same as the number of the energy
level. For example, the first energy level has one sublevel. Its
called the 1s sublevel. The second energy level has two sublevels,
the 2s and 2p sublevels Within a given energy level, the energies
of the sublevels, from lowest to highest, are s, p, d, and f. The
third energy level has three sublevels: the 3s, 3p, and 3d
sublevels; and the fourth energy level has four sublevels: the 4s,
4p, 4d, and 4f sublevels.
Slide 6
The Distribution of Electrons in Energy Levels A specific
number of electrons can go into each sublevel. SublevelNumber of
Atomic Orbitals Maximum Number of Electrons s12 p36 d510 f714
Slide 7
Electron Configurations This most stable arrangement of
electrons in orbitals and sublevels is called an electron
configuration. Electrons fill orbitals and sublevels in an orderly
fashion beginning with the innermost sublevels and continuing to
the outermost.
Slide 8
Get out your PERIODIC TABLES and highlighters / color pencils
of different colors
Slide 9
Sections of Periodic Table to Know f-block s-block d-block
p-block
Slide 10
E LECTRON C ONFIGURATIONS Electron Configurations represent the
location of the electrons in an atom or ion. 1s 2 2s 2 2p 5 the
energy level of the electron (n) the sublevel the number of
electrons
Slide 11
N OTATIONS OF E LECTRON C ONFIGURATIONS Standard Shorthand
Orbital Diagrams
Slide 12
W RITING E LECTRON C ONFIGURATIONS 1. You always start at the
beginning of the periodic table. 2. Use the row number on the
periodic table to give you the energy level (or coefficient) to
use. 3. Use the block on your periodic table to tell you the
sublevel (or letter) to write on your electron configuration. 4.
Count across your periodic table until a. You reach the end of a
block or a row. b. You reach your desired element. This tells you
the number of electrons to write (or the exponent).
Slide 13
Write the ground state electron configuration for hydrogen. 1s
1
Slide 14
Write the complete electron configuration for beryllium. 1s 2
2s 2
Slide 15
Write the electron configuration for chlorine. 1s 2 2s 2 2p 6
3s 2 3 p 5
Slide 16
E LECTRON C ONFIGURATIONS You try these on your own! Fluorine
Potassium 1s 2 2s 2 2p 5 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1
Slide 17
E LECTRON C ONFIGURATIONS ( CONTAINING THE D - SUBLEVEL ) The
energy level of d-sublevel will ALWAYS be one less than the row or
period number.
Slide 18
Write the electron configuration for titanium (Ti). s1s 2 2 2
2p 6 3s 2 3 p 6 4s 2 3 d 2
Slide 19
Write the electron configuration for iron (Fe). s1s 2 2 2 2p 6
3s 2 3 p 6 4s 2 3 d 6
Slide 20
Write the electron configuration for bromine (Br). s1s 2 2 2 2p
6 3s 2 3 p 6 4s 2 3 d 10 4p 5
Slide 21
You try these on your own! Tellurium (Te) Silver (Ag) 1s 2 2s 2
2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 4 1s 2 2s 2 2p 6 3s 2
3p 6 4s 2 3d 10 4p 6 5s 2 4d 9
Slide 22
S HORT -H AND N OTATION [Ne]3s 2 3p 2 Uses a noble gas (Group
18) to represent the innermost electrons. Outermost electrons are
represented the same way. Hint: To find the noble gas, look at the
noble gas from the previous row or the row above the element.
Slide 23
Shorthand Electron Configuration (S.E.C.) To write S.E.C. for
an element: 1. Put symbol of noble gas that precedes element in
brackets. 2. Continue writing e config. from that point.
Slide 24
Write the noble gas electron configuration for silicon. [Ne] s
2 33p 2
Slide 25
Write the noble gas electron configuration for zinc. [Ar] s 2
43d 10
Slide 26
N OBLE G AS E LECTRON C ONFIGURATIONS You try these on your
own! Barium (Ba) Antimony (Sb) [Xe]6s 2 [Kr]5s 2 4d 10 5p 3
Slide 27
O Orbital Diagrams show spins of e and which orbital each is in
1s 2s 2p3s 3p 1s 2s 2p3s 3p P
http://genchem1.chem.okstate.edu/ccli/CCLIDefault.html
Slide 28
O RBITAL D IAGRAMS /E LECTRON C ONFIGURATION hydrogen helium
carbon 1s 1 1s 2 2s 2 2p 4
Slide 29
V ALENCE E LECTRONS Valence electrons are electrons found on
the highest energy level. They are always s or s and p electrons.
There can be no more than eight valance electrons. 1s 2 2s 2 2p 6
3s 2 3p 2 What is the highest energy level? n =3 or third energy
level How many electrons are on the highest energy level? 4
electrons How many valence electrons are in this element? 4
electrons
Slide 30
S AMPLE Q UESTIONS Write the electron configuration (the long
way or short hand notation) for the following elements. For each
element, determine the number of valence electrons. 1. Calcium 2.
Nitrogen 3. Arsenic 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 or [Ar]4s 2 2
valence electrons 1s 2 2s 2 2p 3 or [Ne] 2s 2 2p 3 5 valence
electrons 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 3 or [Ar] 4s 2 3d
10 4p 3 5 valence electrons
Slide 31
L EWIS D OT D IAGRAMS Element Symbol One Dot for Each Valence
Electron
Slide 32
L EWIS S TRUCTURES 1) Find your element on the periodic table.
2) Determine the number of valence electrons. 3) This is how many
electrons you will draw.
Slide 33
L EWIS S TRUCTURES Find out which group (column) your element
is in. This will tell you the number of valence electrons your
element has. You will only draw the valence electrons.
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Slide 34
G ROUPS - R EVIEW Each column is called a group Each element in
a group has the same number of electrons in their outer orbital,
also known as shells. Except for He, it has 2 electrons The
electrons in the outer shell are called valence electrons
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Slide 35
N
Slide 36
L EWIS S TRUCTURES 1) Write the element symbol. 2) Carbon is in
the 4 th group, so it has 4 valence electrons. 3) Starting at the
right, draw 4 electrons, or dots, counter-clockwise around the
element symbol.
Slide 37
L EWIS S TRUCTURES
Slide 38
Slide 39
S AMPLE Q UESTIONS How to Place the Dot on Any Symbol Draw the
Lewis dot diagrams for the following elements. Silicon Sodium
Iodine X Si Na I