Part I

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

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

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.