Chemistry, Brief history

Big Chem Historical Introduction

NATURAL PHILOSOPHY-- Old name for Science (Greek for “Love of Knowledge ”).

THALES OF MILETUS (600 BC)-- First Natural Philosopher we know of who hypothesized on the makeup of matter. I. Water is the universal element.Evidences: Heating substances ---> water.ie. leaf, wood, paper, chalk, minerals (the water of hydration). When the Heat's On-- You Sweat! II. The Water Cycle-- shows how water interacts everywhere.III. Concluded: “Nature follows a pattern of laws.”

DEMOCRITUS (400 BC)-- First Atomic Hypothesis.

Atomos: Greek for “uncuttable ”.Chop up a piece of matter until you reach the atomos.

Properties of atoms:Indestructible.Changeable, however, into different forms.An infinite number of kinds so there are an infinite number of elements.Hard substances have rough, prickly atoms that stick together.Liquids have round, smooth atoms that slide over one other.Smell is caused by atoms interacting with the nose-- rough atoms hurt (stink), etc.Sleep is caused by atoms escaping the brain.Death-- too many escaped or didn't return.The heart is the center of anger.The brain is the center of thought.The liver is the center of desire. “Nothing exists but atoms and space, all else is opinion”.

EMPEDOCLESE (400 BC)-- The Four Element Hypothesis:

Primary Matter-- Fire, Water, Earth, Air.The Four Qualities-- Wet, Dry, Warm, Cold.

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Sample formulas:Human flesh-- equal quantities of the Four Elements.Bones-- 1/2 Fire, 1/4 Earth, 1/4 Water.