PER EB/1

PER 2/3

PER 5/6

PER 7/8

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 • Intensive
• Physical • Extensive

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

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

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 • Considerably stronger than ionic bonds
• As a result of this exchange, ions are formed.
• COVALENT
• Sharing of electrons in valence shells to satisfy octet rule for all atoms involved

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 • MOLECULE
• Def: Matter comprised of two ore more different elements
• Ex: NaCl, H
2
0, CCl
4
• 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 • INORGANIC
• Contains carbon • Does not contain carbon
• Ex: C0
2
, CCl
4
, C
6
H
12
O
6
• H
2
O, NaCl, H
2
SO
4