Download The Periodic Table

 Describe
how Mendeleev arranged the
elements in the periodic table
 Explain how the predictions Mendeleev made
and the discovery on new elements
demonstrated the usefulness of his periodic
table
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1. Antoine Lavoiser
- organized known elements (very few) into
metals, non metals, gases, and earth metals
2. Dmitri Mendeleev
- organization based on a popular card game
solitaire
- each card had the elements name, mass, and
properties
- lined up the cards in order of increasing mass,
found a pattern
- elements with similar properties were in the
same
column
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Predictions
- could not make a complete table, only had 63
elements leaving many spaces between
elements
- 3. used properties of other elements to predict
undiscovered elements properties
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Evidence
named some of the missing elements, and
predicted some of their properties. Ex. Ekaaluminum, eka-iodine…)
4. as elements were found scientists were
able to verify properties and even explain
chemical behaviors of elements in groups
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5.Medeleev’s periodic table was completed before
the discovery of protons.
by looking at certain trends, among the elements a
new organization was created
6. Periodic Law
- pattern of repeating properties displayed by
elements in the periodic table
7. SO….the periodic table is now arranged by atomic
number instead of atomic mass
Describe the arrangement of elements in the
modern periodic table
 Understand the trends that established the
modern periodic table
 Locate periods and groups in the period
table
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Definition
- An electron that is in the highest occupied
energy level of an atom
- Determines the chemical properties of elements
Valence Electrons
Label your periodic table now
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Definition
- Atoms tend to gain or lose electrons based on
how many valence electrons they have.
Ions are atoms or groups of atoms that have a
positive or negative charge
Chemical Bonding
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Atoms of elements are not chemically stable
until they have 8 valence electrons .
Atoms gain, lose or share electrons with
other atoms to become chemically stable
(have 8 valence electrons ).
-Cations (+): Ions that have lost electrons,
has more positive protons than negative
electrons (Metals)
- Sodium loses an electron and
becomes a cation when it combines with
other elements (Na+)
- Anion (-): Ions that have gained
electrons, has more negative electrons than
positive protons (non metals)
- Chlorine gains an electron and
becomes an anion and now ends in ide:
Chloride Cl-
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This will determine the formula of IONIC
Compounds
A
chemical compound in which
ions are held together in a lattice
structure by ionic bonds.
 They are composed of a metal
(cation) and a nonmetal (anion)
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Three Regions
- metals, and nonmetals, and metalloids
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Metals
- include group 1 -12 and some elements
from 13 -16
- most known elements
- good conductors of electricity/heat
- solid at room temperature, except mercury
ex. Na, Ag, Pb
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Definition
- elements with properties that fall between
those of metals and non metals
- chemical properties will vary, usually
most like the region they are closer to
ex. As: closer to non metal most of
it’s property will
resemble that
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Definition
- elements that are poor conductors of
electricity/heat
- low boiling points, SO…most are gases at
room temperature
- varying chemical properties
ex. He, F, P
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An ionic compound is a chemical compound
in which ions are held together in a lattice
structure by ionic bonds.
Consists of a cation (metal) and an anion
(nonmetal)
Examples:
NaCl
Sodium Chloride
MgO
Magnesium Oxide
LiBr
Lithium Bromide
K3N
Potassium Nitride
Write a formula for potassium
sulfide.
1. Identify the cation and anion.
potassium
= K+
sulfide
= S2−
2. Balance the charges.
K+
S2−
K+
2(1+) + 2(1-) = 0
3. 2 K+ and 1 S2− =
K2S
1. Write the charge of the
cation as a superscript.
2. Write the charge of the
antion as a superscript.
3. Criss cross the superscripts
and make them subscripts
4. Reduce when possible.
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Sodium Chloride
Magnesium Oxide
Lithium Bromide
Potassium Nitride
Calcium Oxide
Aluminum Sulfide
Iron (II) Oxide
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Transition Metals have variable charges that
will be indicated by a Roman Numeral.
Ex : CrO3 Chromium (III) Oxide
Polyatomic Ions have their own names
Ex: CaSO4 Calcium Sulfate
Acids have different naming rules. Acids always
start with Hydrogen
Ex: H2SO4 Sulfuric Acid
Memorize the
left side by
next class
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Atomic Radii:
- half the distance between the nuclei of the same
atoms bonded together
-Atomic Radius increases down a group and
decreases across a period from left to right
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Ionization energy:
- amount of energy required to pull an
electron away from an atom to form a
positively charged ion
- generally increases with increasing
atomic number
- at some points, when atomic number
increases there is a dramatic decrease
ex. Li, Na, K, Rb, Cs, Fr
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Electronegativity is the tendency of an atom
to attract a bonding pair of electrons.
Electronegativity also generally increases with
increasing atomic number across a period
from left to right and increases moving up a
group.
Fluorine is the most electronegative element
while Cesium and Francium are the least.
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Electron affinity is the energy released when
an atom gains an electron.
Decreases from top to bottom in a group and
increases from left to right across a period.
Shielding or nuclear shielding is a term used
to describe the core electrons ability to shield
the valence electrons from the charge of the
nucleus.
The larger the atomic radius the higher the
shielding effect is within an atom.
7 periods (Across)
- Atomic Radius decreases
- Ionization energy increase
- Electron Affinity increases
18 Groups (Down)
- Atomic Radius increases
- Ionization energy decreases
- Electron affinity decreases
- Elements have similar chemical and physical
properties
- # of valence electrons are the same
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Families/Groups
Alkali metals
Alkali Earth metals
Boron Family
Carbon Family/ Chalcogens
Nitrogen Family
Oxygen Family
Transition Metals
Halogens
Noble Gases
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Unlike any other element
Very reactive
Gas at room temperature
Belongs to it’s own group of one.
Most common element in the universe
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Definition
- highly reactive metallic elements in group 1
- react violently with water to form hydrogen and
alkaline solutions
- Must be stored in oil, burn when exposed to air
- al-quili means wood ashes
- one outer electron, by losing this electron they
become a cation, and become stable
- Low density and low MP
- soft metals; can be cut with a knife
- shiny, but dull quickly due to oxygen and water
in air
- good conductors
- gaseous states at high temperatures become
plasmas
ex. Na, Cs, Rb
Ex: See Video Demo
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Definition
- comes from idea of “Earth”, materials
unable to light on fire
- Occur as carbonates, phosphates, sulfates
- Mostly form ionic compounds
- reactive metallic elements with two
electrons in the outermost energy level
- harder, denser, stronger and have higher
melting points, lower reactivity than alkali
ex. Be, Ca, Mg
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Groups 3-18
Contain 1 or 2 valence electrons
Brittle metals
High MP and BP
Excellent conductors of electricity and heat
Most are silver except for copper and gold
Include radioactive elements 89-112
Includes Mercury(Hg), only liquid metal at RT
Tend to have 2 or more oxidation states so
their ionic charge may vary
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Lanthanides
- shiny, metallic transition metals (58 – 71) in
which electrons are added to 4f orbitals
- located at the bottom of the periodic table for
convenience
Actinides
-shiny metallic transition metals (90 – 103) in
which electrons are added to 5f orbitals
-located at the bottom of the periodic
table for convenience
-radioactive
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Do not occur elementally in nature except
aluminum, which is the most abundant
metallic element
All are metals except Boron which is a
metalloid
Low Melting points
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From the Greek word for “Ore-Forming” since
they are all found in copper ore.
Includes a nonmetal, C, 2 metalloids, Si & Ge,
and 2 metals, Sn & Pb.
Tend to form covalent bonds except for tin
and lead which form ionic bonds
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Consists of 2 nonmetals, N & P, 2 metalloids,
As & Sb, and one metal, Bi.
Nitrogen and Phosphorous are abundant in
the atmosphere
Properties vary widely
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Occur elementally in nature in a diatomic or
polyatomic state
Tend to form covalent bonds
Consists of 3 nonmetals(O,S, Se), one
metalloid, Te, and one metal, Po
Properties Vary
Term comes from Greek means “salt former”
 Combines with many metals to form salts
 Nonmetallic elements that have 7 valence
electrons
 Most reactive group of nonmetals
 varying physical properties, similar chemical
properties
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Characterized by low reactivity and by an octet of
electrons (happy)
 Term comes from noble people, did not associate
with anyone other then their kind
 Helium only has 2 electron and is considered full
 All are colorless, odorless gases
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