Transcript Day 31 Periodic Trends - WaylandHighSchoolChemistry

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Review
Movie
Notes
Homework
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K
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Cu
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Br
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Xe
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Complete Electron configuration
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Orbital Diagram
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Bohr’s Model
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Chlorine consists of the following isotopes:
Isotope
Mass
Abundance
35Cl
34.96885
75.771%
37Cl
36.96590
24.229%
Calculate the weighted average atomic mass.
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Dalton, Thomson, Rutherford and Bohr.
Schrödinger and Heisenberg, and many, many
more. Used their brains to venture in the realm
of inner space and found the world of the atom
was a weird and wondrous place.
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Dalton did experiments and said, “I think it’s
clear, atoms are tiny indestructible spheres.”
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Thomson worked with cathode rays and said,
“I disagree. A plum-pudding model makes
much more sense to me.”
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A new chapter in atomic theory started to
unfold when Rutherford played around with
atoms made of gold. When a few of his alpha
particles came bounding back, he hypothesized
a nucleus had knocked them off the track.
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Dalton, Thomson, Rutherford and Bohr.
Schrödinger and Heisenberg, and many, many
more. Used their brains to venture in the realm
of inner space and found the world of the atom
was a weird and wondrous place.
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Bohr saw spectral lines for hydrogen and said,
“It seems to me.. Electrons move in orbits with
specific energies.”
electron
neutron
proton
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Heisenberg said, “Forget it, there’s no way to
know the orbit or a path, where the electron’s
gonna go.”
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Schrödinger used lots and lots of fancy
mathematics, and made a model of the atom
based on quantum mechanics. It has orbitals
and those are based on probability. The atom
is a fuzzy blob of pure uncertainty.

Dalton, Thomson, Rutherford and Bohr.
Schrödinger and Heisenberg, and many, many
more. Used their brains to venture in the realm
of inner space and found the world of the atom
was a weird and wondrous place.
Date:
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With the PT arranged by atomic number,
trends appear within the physical properties
of the elements both periodically and within
a family
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The size of an atom
Periodic Trend
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Decreases with increase in nuclear charge
 Number of protons
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Protons pull electrons in with greater force
Family Trend
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Increases with increase in number of energy levels.
Each new period adds an additional orbit.
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Cations
 Smaller than parent atom
 Lost e- emptying energy level and nucleus
can pull remaining e- closer.
Anions
 Larger than parent atom
 Gained e-; electrons repel each other so size
enlarged.
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The energy required to remove an electron
Periodic Trend
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Increases with increased nuclear charge
Electrons are closer to nucleus which does not want
to lose its electrons
Family Trend
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Decreases with additional energy levels
Electrons are further from nucleus and easier to
remove; shielding
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The ability to attract an electron
Periodic Trend
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Increases with increased nuclear charge
Nucleus provides a stronger pull
Family Trend
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Decreases with each additional energy level
Shielding
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Ability to react with other chemicals.
Family Trend for metals
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Increases down a family
Family Trend for nonmetals
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Decreases down a family