Chemical Bonding When two or more atoms join a bond is formed
It will not fall apart unless enough energy is added to break the
bond The type of bond determines certain properties of the
compounds they create
Slide 4
Why do atoms bond? Octet Rule: Atoms tend to gain, lose, or
share electrons so as to have 8 electrons in their outermost shell
(except for H and He)
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Types of Bonds There are three main types of bonds: Ionic Bond
Covalent Bond Metallic Bond
Slide 7
Learning Check: When two or more atoms join, a _________ forms.
Bond How many electrons do most atoms want in their outer shells? 8
What are the three types of bonds? Ionic, Covalent, and
Metallic
Slide 8
IONIC BOND bond formed between two ions by the transfer of
electrons
Slide 9
Ionic Bonds Form between metals and nonmetals Involves the
transfer of electrons The metal gives away electron(s) becoming a
positive ion The nonmetal gains electron(s) becoming a negative ion
The charged atoms are held together because the positive and
negative forces are attracted to one another
Slide 10
Ionic bond electron from Na is transferred to Cl, this causes a
charge imbalance in each atom. The Na becomes (Na+) and the Cl
becomes (Cl- ), charged particles or ions.
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Slide 12
Ionic Bonds: One Big Greedy Thief Dog!
Slide 13
Properties of Ionic Bonds Network solids High melting and
boiling points Conduct electricity when melted Many soluble in
water but not in nonpolar liquid
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Learning Check: When a bond is formed by the transfer of
electrons, a __________ bond is formed. Ionic These bonds form
between Metals and nonmetals The metals lose electrons to the
nonmetals to create positive and negative ________. Ions
Slide 15
COVALENT BOND bond formed by the sharing of electrons
Slide 16
Covalent Bonds Form between nonmetals Involves the sharing of
electrons The nonmetals share one or more pairs of electrons to
have a full octet Two types: polar and nonpolar
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Two Types: Determined by how electrons are shared Based on
electronegativity Shared evenly = Nonpolar Shared unevenly =
Polar
Slide 19
Non polar Covalent Bonds when electrons are shared equally H 2
or Cl 2 Oxygen Atom Oxygen Molecule (O 2 ) Oxygen Molecule (O 2
)
Slide 20
Nonpolar Covalent Bonds: Evenly matched, but willing to
share.
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Polar Covalent Bonds when electrons are shared but shared
unequally H 2 O
Slide 22
Polar Covalent Bonds: Unevenly matched, but willing to
share.
Slide 23
Properties of Covalent Bonds Gases, liquids, or solids Low
melting and boiling points Poor electrical conductors in all phases
Many soluble in nonpolar liquids but not in water
Slide 24
Learning Check: When a bond is formed by the sharing of
electrons, a __________ bond is formed. Covalent These bonds form
between Nonmetals When atoms have different electronegativities,
and share electrons unevenly, a ________ molecule is formed.
Polar
Slide 25
METALLIC BOND bond found in metals; holds metal atoms together
very strongly
Slide 26
Metallic Bonds Form between metals Involves the overlapping of
outer energy levels Attraction between one atoms nucleus and a
neighboring atom's electrons packs the atoms closely together
Allows electrons to move freely from one atom to another.
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Metallic Bonds: Mellow dogs with plenty of bones to go
around.
Slide 29
Properties of Metallic Bonds Form alloys Examples: steel,
brass, bronze and pewter Metals conduct electricity well do to the
freedom of the electrons to move. Metals are flexible because the
atoms can slide past each other without their bonds breaking.
Slide 30
Identifying Types of Bonds 1. Look at the chemical formula 2.
Identify the elements in the compound 3. Determine if the elements
are metals or nonmetals (using a periodic table) 4. Metal Metal =
Metallic 5. Metal Nonmetal = Ionic 6. Nonmetal -- Nonmetal =
Covalent 1. Polar Covalent = different atoms/elements 2. Nonpolar
Covalent = same atoms/elements
Slide 31
Remember: Metals are on the left of the periodic table, and
nonmetals are on the right.
Slide 32
Learning Check: Identify the type of bond present in each
compound: CH 4 Carbon = Nonmetal Hydrogen = Nonmetal Covalent Bond
(polar) LiBr Lithium = Metal Bromine = Nonmetal Ionic Bond FeCl 3
Iron = Metal Chlorine = Nonmetal Ionic Bond O 2 Oxygen = Nonmetal
Covalent Bond (nonpolar )
Slide 33
Polyatomic Ions Compounds that contain polyatomic ions contain
both ionic and covalent bonds Involves groups of covalently bonded
atoms that have either lost or gained electrons. Parenthesis group
the atoms of a polyatomic ion to remind you that they act as one
ion. Pg. 158 contains a list of many common Polyatomic Ions.
Slide 34
Learning Check: Identify the type of bond present in each
compound: MgCl 2 Magnesium = Metal Chlorine = Nonmetal Ionic Bond
NH 4 Cl Ammonium = Polyatomic Ion Chlorine = Nonmetal Both; Ionic
and Covalent NaOH Sodium = Metal Hydroxide = Polyatomic Ion Both;
Ionic and Covalent NO 2 Nitrogen = Nonmetal Oxygen = Nonmetal
Covalent Bond (polar )
