Transcript Mr. Farnworth

Mr. Bean
Discovery Science
Bonding
• Bond: Attraction between 2 or more atoms
or ions
• Two broad classifications
• Ionic (attraction between cations & anions)
• Covalent (electron sharing)
BONDING
• Covalent Bonding- a bond formed when
two atoms share one or more pairs of
electrons
• Covalent Compounds- Compound in
which electrons are shared- Non-metals
only
IONIC
• Ionic bond- A bond that forms when
oppositely charged species attract to one
another
• Ionic compound- Electrically neutral
species combing cations and anions.
IONS
• Electrically charged
objects that consists
of an atom or group of
atoms
Cations and Anions
• Cations-Chemical
species with a
positive charge
• Anions-chemical
species with a
negative charge
Polyatomic Ions
• Species consisting of
two or more atoms
• A non-metal often
combines with
another non-metal to
form an ion containing
two or more atoms
Some common Polyatomic
Anions
Ion name
Ion formula
-
Hypochlorite ion
ClO
Hydrogen sulfate ion
HS04-
Sulfate ion
Phosphate ion
2SO
4
PO
3-
4
Nitrate ion
NO-3
SOME COMMON CATIONS
ION NAME AND
SYMBOL
Sodium ion, Na+
2+
Barium ion, Ba
3+
Aluminum ion, Al
ION CHARGE
1+
2+
3+
Organic and Biochemical
Compounds
• Organic compound- any covalently
bonded compound that contains CARBON
• Carbon atoms form FOUR covalent bonds
in organic compounds
• Methane CH4 (Draw structure)
• Carbon atoms have four valence electrons
for bonding. Each of theses electrons
forms a different C-H Bond
Carbon
• Carbon atom may also share two of its
electrons with two from another atom to
form an double bond. (up to three)
• A carbon atom can never form more than
a total of four bonds
• Alkanes are hydrocarbons that have only
SINGLE covalent bonds
• C-H BONDS
• C-C BONDS
• Ethane C2H6
• Alkanes see table p264
Alkanes
• Chemical formulas for alkanes follow a
special pattern.
• # of hydrogen atoms always twice more
than the number of Carbon atoms.
• Alkenes are hydrocarbons.
• Alkenes are different from alkanes
because they have at least one double
• p266 covalent bond between carbon
atoms.
Alcohol (p273)
• Alcohol have -OH groups
• Organic compounds that are made of
oxygen as well as carbon and hydrogen
• Have HYDROXYL or -OH groups.
• Methanol, CH3OH
• Behave similarly to water molecules
• Just like water molecules, neighboring
alcohol molecules are attracted to one
another
Alcohols
• Have much higher boiling points than
other organic compounds of similar size
• A large organic molecule made of many
smaller bonded units.
• DNA, wood, rubber, plastic
• Small organic molecules bond to form
long chains
• Natural and Man-made
• p275
Polymers
• Elasticity of a polymer is determined by
its structure
• long thin chains
• single fiber is made of billions of these
chains
• When chains are connected ,or cross
linked(tennis net) the polymer becomes
more elastic
• rubber bands are elastic polymers
Biochemical Compounds
• Any organic compound that has an
important role in living things
• Carbohydrates-glucose and starch
• Proteins are polymers of amino acids
• Amino Acids- are made of carbon,
hydrogen, oxygen and nitrogen