PER EB/1

PER 2/3

PER 5/6

PER 7/8

February 19th, 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, H20, CCl4

• MOLECULE

• Def: Smallest unit of a chemical substance that retains properties of that same substance

• Ex: C6H12O6, Cl2, H2O

What’s The Difference?

• ORGANIC

• Contains carbon

• Ex: C02, CCl4, C6H12O6

• INORGANIC

• Does not contain carbon

• H2O, NaCl, H2SO4