partial orbital diagram and condensed configurations...categories of electrons inner (core)...
TRANSCRIPT
Partial Orbital Diagram and
Condensed Configurations
Partial orbital diagram: shows only the
highest energy sublevels being filled.
Condensed electron configuration: has
the element symbol of the previous
noble gas in square brackets
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Al (Z = 13) 1s22s22p63s23p1 ↑↓
3s 3p
↑
Al has the condensed configuration [Ne]3s23p1
Learning Check
Full Electron
Configuration
Element Condensed
Electron
Configuration
Partial
Orbital
Diagram
1s22s22p63s1 Na [Ne]3s1
1s22s22p63s2 Mg [Ne]3s2
1s22s22p63s23p4 S [Ne]3s23p4
1s22s22p63s23p5 Cl [Ne]3s23p5
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Electron Configuration and
Group
Elements in the same
group have the same outer
electron configuration
Similar outer electron
configurations correlate
with similar chemical
behavior.
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Period 4 Elements
Write the full and
condensed electron
configuration of
the following
elements:
◦ Ca (20)
◦ Ti (22)
◦ Mn (25)
◦ Ni (28)
◦ As (33)
◦ Kr (36)
4
Period 4 Elements
5
*Colored type indicates the sublevel to which the last electron is added.
Period 4 Elements
6
*Colored type indicates the sublevel to which the last electron is added.
Orbital Filling
and the Periodic Table
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The order in which the orbitals are filled can be obtained directly
from the periodic table.
Categories of Electrons
Inner (core) electrons: are those an atom
has in common with the previous noble gas
and any completed transition series.
Outer electrons: are those in the highest
energy level (highest n value).
Valence electrons: are those involved in
forming compounds.
◦ For main group elements: outer electrons
◦ For transition elements: outer electrons and
any (n-1)d electrons
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Learning Check
Give the condensed electron
configurations, partial orbital
diagrams showing valence electrons
only, and number of inner electrons
for the following elements:
◦ Potassium (K, Z=19)
◦ Technetium (Tc, Z=43)
◦ Lead (Pb, Z=82)
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Sample Problem 8.2
SOLUTION:
(a) For K (Z = 19)
[Ar] 4s1 condensed configuration
1s22s22p63s23p64s1 full configuration
There are 18 inner electrons.
partial orbital diagram
↑
4s 4p 3d
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Sample Problem 8.2
SOLUTION:
(b) For Tc (Z = 43)
[Kr]5s24d5 condensed configuration
1s22s22p63s23p64s23d104p65s24d5 full configuration
There are 36 inner electrons.
partial orbital diagram
↑↓
5s 5p 4d
↑ ↑ ↑ ↑ ↑
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Sample Problem 8.2
SOLUTION:
(c) For Pb (Z = 82)
[Xe] 6s24f145d106p2 condensed configuration
1s22s22p63s23p64s23d104p65s24d105p66s24f145d106p2 full configuration
There are 78 inner electrons.
partial orbital diagram ↑↓
6s 6p
↑ ↑
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Trends in the Periodic Table
1. Atomic Size
2. Ionization Energy
3. Electron Affinity
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Defining atomic size
Atomic size: an approximation of the
space between adjacent nuclei
15 Metallic radius Covalent radius
Trends in Atomic Size
Influenced by 2 factors:
◦ Down a group, n dominates: As n increases,
the probability that the outer electrons
will be farther from the nucleus increases.
◦ Across a period, Zeff dominates: As Zeff
increases, the outer electrons are pulled
closer to the nucleus.
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What is Zeff?
Inner core electrons “shield” outer electrons
from the positive charge of the nucleus.
Zeff (effective nuclear charge) is the force
felt by the outer valence electrons taking
into account the “shielding” effect by core
electrons.
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Periodicity of Atomic Radius
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Learning Check
Using only the periodic table, rank
the elements in each set in order of
increasing size.
◦ Se, Br, Cl
◦ I, Xe, Ba
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Cl < Br < Se
Xe < I < Ba
Trends in Ionization Energy (IE)
IE is the energy required to remove 1
mole of electrons from 1 mole of a
gaseous atom in its ground state.
𝐼𝐸1 + 𝑋(𝑔) → 𝑋(𝑔)+ + 𝑒−
𝐼𝐸2 + 𝑋(𝑔)+ → 𝑋(𝑔)
2+ + 𝑒−
𝐼𝐸3 + 𝑋(𝑔)2+ → 𝑋(𝑔)
3+ + 𝑒−
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IE1 < IE2 < IE3
Trends in Ionization Energy (IE)
As atomic size decreases, it takes more
energy to remove an electron.
Atoms with a low IE tend to form cations.
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This trend is the inverse of the trend in atomic size. 23
Learning Check
Rank the elements in each of the
following sets in order of increasing
first ionization energy.
◦ Sb, Sn, I
◦ Sr, Ca, Ba
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Sn < Sb < I
Ba < Sr < Ca
Successive Ionization Energies
The first three ionization
energies of beryllium
(Z=4).
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Successive Ionization Energies
Drastic jump in IE occurs after outer
(valence) electrons have been
removed.
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Identifying an Element Based on
its IE
Name the Period 3 element with the
following ionization energies (in
kJ/mol) and write its electron
configuration:
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IE1 IE2 IE3 IE4 IE5 IE6
1012 1903 2910 4956 6278 22,230
Phosphorus, 1s22s22p63s23p3