Download COMPOUNDS AND MOLECULES

4.1 COMPOUNDS AND
MOLECULES
ELEMENTS – a review…
• Made of individual atoms.
• Cannot be broken down into simpler
substances.
• Listed on the periodic table.
• Created to be the building blocks of all
matter.
MIXTURES – a review…
– Different substances just placed
together.
– Substances keep their individual
properties.
– Easily separated like sand and
gravel.
COMPOUNDS
• Two or more
elements bonded
together =
COMPOUND.
• Have properties
different from the
original element.
– Have a chemical
formula
– Not easily separated.
– New properties!!!!
MODELS OF
COMPOUNDS
A. BALL AND STICK
B. SPACE FILLING
C. STRUCTURAL FORMULA
STRUCTURE
AND
PROPERTIES
A. Network structure - ATOMS
SiO2 (strong, rigid, high melting point)
EXAMPLE:
B. Network structure - IONS
NaCl (strong, rigid, high melting point)
EXAMPLE:
C. Molecule groups
C12H22O11 (weak bonds, low melting
point)
EXAMPLE:
4.2 IONIC, METALLIC,
AND COVALENT
BONDING
How could you get pieces of paper to bond
(stick together)?
Atoms BOND (stick together)
when their outer energy level
(VALENCE) electrons interact.
There will be THREE different
kinds of bonding.
1. IONIC BONDS
• Electrons are transferred from one atom to
another creating ions.
• Then the bond is formed between oppositely
charged ions.
• Ionic compounds are in the form of a network
of particles.
• Ionic compounds conduct electricity when
melted or dissolved in water.
2. METALLIC BONDS
• Electrons are free to move from atom to
atom.
• Atoms are tightly packed together.
• Metals are: flexible, can bend and stretch,
and can conduct electricity.
3. COVALENT
BONDS
• Formed when atoms
share electrons.
• Often form from
nonmetals.
• Most have low melting
points.
• Do not conduct
electricity well.
BONDING SUMMARY
(how to tell what type of bond is
holding a molecule together)
Periodic Table
NONMETAL
METAL
METAL + NONMETAL =IONIC
NONMETAL + NONMETAL =
COVALENT
METAL+ METAL = METALIC
POLAR AND NONPOLAR
COVALENT BONDS
POLAR
DIFFERENT TYPES OF
ATOMS DO NOT
SHARE ELECTRONS
EQUALLY
NONPOLAR
ATOMS OF THE SAME
TYPE SHARE THE
ELECTRONS
EQUALLY
WORKING WITH
MODELS 4.2B
H2
H20
NaCl
COVALENT
COVALENT
IONIC
H-H
H-O-H
Na-Cl
Cl2
O2
N2
COVALENT
Cl-Cl
O=O
N N
CO2
C2H2
COVALENT
COVALENT
DOUBLE COVALENT
TRIPLE COVALENT
O=C=O
H-C C-H
4.3
COMPOUND NAMES AND
FORMULAS
Figuring out how to do assignment
#1…Where do I start???
TYPES OF IONS
CAtION – ION WITH A
POSITIVE (+) CHARGE
ANION – ION WITH A
NEGATIVE (-) CHARGE
PERIODIC TABLE
METALS
+
1
+
2
NONMETALS
TRANSITION
METALS
+1 OR +2
CATIONS
2
1
ANIONS
N
O
B
L
E
G
A
S
POLYATOMIC IONS
NAMING IONIC
COMPOUNDS
NaCl (Cl-)
Sodium Chloride
(Na+)
(Mg2+)
Mg + F (F-)
MgF2
Magnesium Flouride
NAMING COVALENT
COMPOUNDS
ELEMENTS GET A NUMERICAL
PREFIX THAT INDICATES HOW
MANY ATOMS ARE PRESENT –
(table 4-7)
ELEMENTS TO THE RIGHT ARE
NAMED SECOND AND END IN
“IDE”
4.4 ORGANIC COMPOUNDS
What does it mean to be
organic?
This is the common
definition…
In Chemistry, an
ORGANIC
COMPOUND…
• Contains the element
CARBON and ALMOST always
HYDROGEN.
• CARBON is a SPECIAL ATOM:
BECAUSE IT CAN BOND WITH
FOUR OTHER ATOMS. (valence
4)
HYDROCARBONS
• Contain ONLY HYDROGEN and
CARBON
ALKANE – a special
hydrocarbon
• Hydrocarbons with SINGLE
COVALENT BONDS
• The simplest one is: CH4 =
METHANE (table 4-9)
• Others may form CHAINS,
BRANCHES, or RINGS of
hydrogen and carbon.
ALKENE – another type of
hydrocarbon
• A hydrocarbon with DOUBLE
COVALENT BONDS
C2H4 = ETHYLENE
ALCOHOL – another
organic molecule
• Alcohols contain the: (OH)
atom group
• CH3OH = METHANOL
• The rest just add (OH) to the
appropriate alkane in table
4-9….
POLYMERS
• SMALL ORGANIC MOLECULES
THAT BOND TO FORM LONG
CHAINS OF MOLECULES:
C2H4….= POLYETHYLENE
• Some polymers are NATURAL
CREATIONS of God: WOOD,
STARCH, PROTEIN.
• Some polymers are MAN-MADE:
•
•
•
•
•
•
CHAPTER FOUR TEST
STUDY THIS:
MIXTURE or COMPOUND
NETWORK structure or MOLECULE group
IONIC bond or COVALENT bond
Will a substance conduct electricity? Explain.
Chapter vocabulary words
ION location on the Periodic Table (notes)