Early Ideas About Matter

Early Ideas About Matter

1. Greek Philosophers

   • Democritus
     • Matter is composed of atoms which move through empty space
     • Atoms are solid, homogeneous, indestructible, and indivisible
     • Different kinds of atoms have different shapes and sizes
     • Size, shape, and movement of atoms determine the properties of matter
   • Aristotle
     • Matter is made of earth, fire, air, and water
     • Empty space does not exist

2. Defining the Atom

   • The smallest particle of an element that retains the properties of that element

3. John Dalton

   • Dalton's Atomic Theory
     • Matter is composed of extremely small particles called atoms
     • Atoms are indivisible and indestructible
     • Different atoms combine in simple whole-number ratios to form compounds
     • In a chemical reaction, atoms are separated, combined, or rearranged
     • Atoms of a specific element are different from those of another element
     • Atoms of a given element have identical size, mass, and chemical properties