History of the Atom Part I
Democritus 460 BC - Develops the idea for atoms • He pounded up materials in his pestle and mortar until he had reduced them to smaller particles • He determined that everything is made up of smaller, indivisible particles, which he called atoms. • Atoma is greek for indivisible
John Dalton 1803 – Atoms are the fundamental building blocks of matter (5 postulates) • Was fascinated with meteorology and from his work studying gasses, he theorized certain ideas regarding atoms. • There were 5 major concepts in Dalton’s Atomic Theory
Daltons Atomic Theory • All matter is made of indivisible and indestructible atoms • All atoms of a given element are identical in their physical and chemical properties. • Atoms of different elements combine in simple whole-number ratios to form compounds • Chemical reactions consist of the combination, separation, or rearrangement of atoms.