PER EB/1

PER 2/3

PER 5/6

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February 19 th, 1994

DMSO = Dimethyl Sulfoxide

A Change…

The Structure of Matter “Nature uses only the largest threads to weave her patterns, so each small piece of her fabric reveals the organization of the entire tapestry” –-Richard Feynman

What’s The Difference? BIOLOGY Study of the structure, organization and interaction of living organisms CHEMISTRY Study of the structure, organization and interaction of matter

Properties of Matter Chemical Physical Intensive Extensive

CHEMICAL v. PHYSICAL CHEMICAL A property of matter than exists only when the matter interacts with other forms of matter Ex: Oxidation (rusting) PHYSICAL A property of matter that exists whether or not the matter interacts with other forms of matter Ex: Density, Viscosity

INTENSIVE v. EXTENSIVE Intensive Property or characteristic is consistent regardless of the amount of matter present Ex: boiling point, conductivity Extensive Property or characteristic depends upon the amount of matter Ex: mass, pH

These properties are determined by the arrangement of matter on multiple levels

The Atom Atmos = indivisible Three major subatomic particles –Proton –Neutron –Electron

Elements of Biological Interest Oxygen (O) Carbon (C) Hydrogen (H) Nitrogen (N) Calcium (Ca) Phosphorus (P) Potassium (K) Sulfur (S) Sodium (Na) Chlorine (Cl) Magnesium (Mg)

Electron Arrangement Energy levels/orbits Shells hold –2 e- –8 e- –18 e- Valence Electrons are outermost electrons

The Octet Rule Atoms seek stability through having completely full or completely empty valence shells Atoms may gain, lose or share electrons to satisfy these full or empty arrangements. These arrangements are called BONDS The interaction of electrons occurs in the valence (outermost) shells/orbits

IONS Atoms with an imbalance between the number of electrons (-) and protons (+) If protons > electrons, the positively charge atom is a CATION If protons < electrons the negatively charged atom is an ANION

WHAT’S THE DIFFERENCE? IONIC Gain or loss of electrons from valence shells Causes an imbalance in electrical charge As a result of this exchange, ions are formed. COVALENT Sharing of electrons in valence shells to satisfy octet rule for all atoms involved Considerably stronger than ionic bonds

Intermolecular Forces Attractions between positive and negative groups in molecules Electrons are not shared or exchanged Weak, temporary forces Examples: –Hydrogen –Van der Waal –Disulfide –Metallic

WHAT’S THE DIFFERENCE? COMPOUND Def: Matter comprised of two ore more different elements Ex: NaCl, H 2 0, CCl 4 MOLECULE Def: Smallest unit of a chemical substance that retains properties of that same substance Ex: C 6 H 12 O 6, Cl 2, H 2 O

What’s The Difference? ORGANIC Contains carbon Ex: C0 2, CCl 4, C 6 H 12 O 6 INORGANIC Does not contain carbon H 2 O, NaCl, H 2 SO 4