Download Chemical Bonding

Chemical Bonding
PTT
O All matter is made up of ATOMS
O ELEMENTS consist of one type of atom.
O Elements combine to form COMPOUNDS by bonding
together.
O The VALENCE electrons determine whether or not an
atom will form a bond – the atom “wants” its outer
energy shell to be COMPLETE.
O To achieve this STABILITY, the atom will either gain
(become POSITIVE) or lose (become NEGATIVE)
electrons.
O The COMBINING CAPACITY capacity refers to the
number of ELECTRONS that an atom must lose, gain or
share in order to become stable with a full outer shell.
Big Idea!
Just over 110 elements combine with
chemical bonds to form a nearly infinite
number of compounds.
What We’ll Learn
1. Describe how a compound differs from its
component elements
2. Explain what a chemical formula
represents
1. State a reason why chemical bonding
occurs
Why is Chemical Bonding
Important?
Why is Chemical Bonding
Important?
The millions of different
kinds of matter around us are
a result of chemical bonds!
Combining Elements
Sodium Chloride
Sodium Chloride
Why Do Elements Form
Compounds?
Stability in a compound will be achieved
when electrons in the ions that make it up
are gained or lost.
The combining capacity of an atom
depends on the electrons in its outermost
shell. (Valence e-)
Sodium Chloride
Chemical Formulas
Familiar Name Chemical
Formula
Name
Sand
Silicon Dioxide SiO2
Vinegar
Acetic Acid
CH3COOH
Laughing Gas
Dinitrogen
Oxide
N2O
Battery Acid
Sulfuric Acid
H2SO4
Stomach Acid
Hydrochloric
Acid
HCl
What 2 Things Does a
Chemical Formula Tell You?
Ionic Compounds and
Ionic Bonds
Ionic Bonds
O Ionic atoms either GAIN or LOSE electrons between
each other to become stable
O They are now equally, but oppositely charged IONS,
one positive CATION and one negative ANION
Ionic Bonds
O These OPPOSITE charges ATTRACT each other
and they bond together to form a STABLE ionic
COMPOUND
O The energy needed to transfer the electron s
called IONIZATION energy – low ionization
energy is needed for group 1 and 7
O ELECTRONEGATIVITY is the tendency of an
atom to attract electrons
Ionic Bonds: Transfer electrons (gain or lose
electrons) = Cation + anion
Ionic Compounds
O CATIONS tend to LOSE
electrons and become
positive.
O ANIONS tend to GAIN
electrons and become
negative.
O Always between a METAL
(CATION) and NON-METAL
(ANION).
Types of Ionic Compounds
1. Binary Compounds (Two elements):
a. Metal + Non metal (representative elements)
b. Polyvalence Compounds.
2. Ternary Compounds (Three or more elements):
a. Polyatomic Compounds.
3. Acids (Contain two or more elements bonded to
Hydrogen).
* ADD TO GRAPHIC ORGANIZER
Ionic
Compounds
Binary
Compounds
Metal +
Non-Metal
Ternary
Compounds
Polyvalence
Acids
A. Metal + Non-Metal
Nomenclature:
1. Positive ion (cation) is written first.
2. Crisscross charges and balance  neutralize
the compound.
3. Add ending “-ide” to non-metal (anion).
4. No prefixes.
Ex. Sodium and Chlorine
Symbols = Na and Cl
Charges = Na+1 and Cl-1  (+) and (-)
Crisscross the charges = Na1Cl1 = NaCl
*Reduce when possible
Chemical Name: Sodium Chloride
Chemical Formula: NaCl
*Add examples in notes
B. Polyvalence
Compounds
 Transition metals with multiple charges (Cations)
 Examples: Cu+1 and Cu+2
 Roman Numerals in parenthesis indicate the
oxidation number used.
 Example:
Cu+1= Copper (I)
Cu+2= Copper (II)
*Use same rules as before!
Ex. Copper (I) and Oxygen
Symbols: Cu and O
Charges: Cu+1 and O-2  (+) (-2)
Crisscross: Cu2O1 = Cu2O
*Simplify when possible
Chemical Name: Copper (I) Oxide
Chemical Formula: Cu2O
More Examples:
Manganese (IV) Oxide: Mn+4 + O2- --> MnO2
Iron (II) Chloride: Fe+2 Cl-1 
Iron (III) Sulfide:
*Remember: Simplify to simplest terms when
possible. (See example 1)
Summary
What Did We Learn?
1. Describe how a compound differs from
its component elements
2. Explain what a chemical formula
represents
1. State a reason why chemical bonding
occurs
Closure
Please complete the Google Forms
closure found on the class website
under Week 4, Day 1.
Homework
O Ionic Compounds: Names and
Formulas Worksheet
O Quiz: Nomenclature of Ionic
Compounds – W4, D2