Metals

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Metals

• - Found on the left side of the periodic table
• Includes All of groups 1 (except H) and 2,
• also Al (but not B) in group 13.
• All of the transition elements.
• The elements to the right of the transition
  elements
• The lanthanides and actinides (inner transition
  metals)
• Metals tend to lose electrons!

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Metallic Properties Luster most metals have a
silvery white metallic color because they
reflect light of all wavelengths. Ductile,
(capable of being drawn out into a wire)
Malleable (can be hammered into thin
sheets) Most semisolids _at_ room Tº High
electrical conductivity thermal conductivity -
Examples sodium, calcium, gold, aluminum
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Nonmetals

• Found on the right side of the periodic table
• Nonmetals tend to gain electrons!
• Nonmetallic Properties
• Poor reflectors of light,
• Hard or brittle, some are gases or soft solids
• Not malleable or ductile
• Do not conduct electricity,
• Poor conductor of heat
• - Examples carbon, bromine, chlorine, sulfur

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Metalloids or Semimetals

• Found along jagged line on table
• Metalloids lose or gain electrons depending on
  "who they're with!
• Mixture of both types of properties, or
  intermediate type
• Examples B, Si, Ge, As, Sb, Te, At
• (the only metals on the solid "semimetal" line
  are Al and Po)

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Compounds and Chemical Reactions

• Essentially all elements combine to form
  compounds
• Compounds are of two types
• Molecular, formed by shared electrons and
• consist of electrically neutral, discrete
  particles called molecules
• Ionic formed by electron transfer and charged
  particles called ions

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Ionic Compounds ionic crystals that can vary in
size.
Molecular compounds discrete particles or
molecules
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• Chemical formulas are collections of chemical
  symbols that are used to describe elements and
  compounds
• Free elements are not combined with other
  elements in a compound
• Examples Fe (iron), Na (sodium), and K
  (potassium)

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A chemical formula is a symbolic representation
of the composition of a compound in terms of its
constituent elements.
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• Chemical formulas specify the composition of a
  substance
• NaCl is composed of the elements sodium and
  chlorine in a one-to-one (atom) ratio
• Fe2O3 is composed of the elements iron and oxygen
  in a two-to-three ratio
• CO(NH2)2 expands to CON2H4, but there are good
  reasons to write some compounds with parentheses
• Hydrates are crystals that contain water
  molecules, for example plaster CaSO4 2H2O
• When all the water is removed (by heating), the
  solid that remains is said to be anhydrous
  (without water)

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Ions and Ionic Compounds
Atoms that gain or lose electrons are called ions
Positive ions CATIONS Negative ions ANIONS
Atoms that lose electrons form cations Na ? Na
e
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The charges on many representative elements can
be predicted

• Metals form cations
• The positive charge on the cation is the same as
  the A group number of the metal
• Ask How many e- needed to lose to reveal noble
  gas core?
• Nonmetals form anions
• The negative charge on the anion is equal to the
  number of spaces to the right we have to move in
  the periodic table to get to a noble gas
• Ask How many e- needed to gain to make noble
  gas core?

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Ion Typically formed
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Names and Formulas forIonic Compounds
Ionic compounds form when oppositely charged ions
are attracted to each other
NaCl
Resulting compound is electrically
neutral Na Cl (1) (1) 0
Ionic compound names use the cation name followed
by the anion name
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Ionic Bonding is the TRANSFER of electrons from
one element to another.
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Polyatomic Ions
Polyatomic ions are charged groups of covalently
bonded atoms
EOS
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• Rules for writing Formulas of Ionic Compounds
• 1) The positive ion is given first in the
  formula.
• 2) The subscripts in the formula must produce an
  electrically neutral formula unit.
• 3) The subscripts should be the set of smallest
  whole numbers possible.
• 4) The charges on the ions are not included in
  the finished formula of the substance.

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Introduction to Compounds
A molecule is a group of two or more atoms held
together by covalent bonds. Remember Ionic
Compounds form crystals. The term used for Ionic
compounds is "formula unit not molecule!
http//astrobob.areavoices.com/files/2013/04/Water
-molecule-panel-1024x409.jpg
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In a Covalent Bond, atoms SHARE electrons to form
stable pairs.
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Many nonmetals occur as diatomic molecules
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Molecules that contain two atoms bonded together
are called diatomic molecules.
There are 7 elements that occur as diatomic
molecules in nature
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Molecular Compounds
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Empirical and Molecular Formulas
Empirical formula the simplest whole number
ratio of elements in a compound (covalently
bonded)
Molecular formula the actual number of atoms
of elements in a compound
Example Molecular formula of glucose
C6H12O6
EOS
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• Inorganic compounds are substances not considered
  to be derived from hydrocarbons and do not have
  carbon in them.
• The rules for naming, or nomenclature, of simple
  inorganic compound is covered now (organic
  nomenclature is covered later)
• Binary compounds are compounds comprised of two
  different elements
• The goal is to be able to convert between the
  chemical formula and the name

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Formulas and Subscriptsin Molecules
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Binary Molecular Compounds
Compounds that are typically comprised of two
nonmetallic elements e.g., CO, NO, HF
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• The first element in the formula is identified by
  its English name, the second by appending the
  suffix ide to its stem

Chemical Name as
Name as Symbol Stem First Element
Second Element O ox-
oxygen oxide S
sulf- sulfur sulfide
N nitr- nitrogen
nitride P phosph- phosphorus
phosphide F fluor-
fluorine fluoride Cl
chlor- chlorine chloride
Br brom- bromine
bromide I iod- iodine
iodide
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• Many molecular compounds contain hydrogen

Group
Noble Period 14
15 16 17 Gas (18)
2 CH4 NH3 H2O HF
Ne 3 SiH4 PH3
H2S HCl Ar 4 GeH4
AsH3 H2Se HBr Kr 5
SbH3 H2Te HI
Xe
Note The number of hydrogens that combined with
the nonmetal equals the number of spaces to the
right we have to move to get to the noble gas
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• The number of each type of atom is specified with
  Greek prefixes

Greek Prefixes mono- 1 (often omitted)
hexa- 6 di- 2
hepta- 7 tri-
3 octa- 8
tetra- 4
nona- 9 penta- 5
deca- 10
Examples PF5 phosphorus pentafluoride
HCl hydrogen chloride N2O5
dinitrogen pentoxide
Note many compounds have common names, like
water for H2O.
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Names of Binary Compounds
Consider the compounds CO and CO2
The names are further modified by adding prefixes
to denote the numbers of atoms
EOS
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• To name a compound, you can use this flowchart