The word "atom" is derived from the Greek word "atomos", meaning indivisible. The philosopher Democritus (460-370 B.C.) believed that matter was composed of fundamentally indivisible particles, called "atomos".

Dalton's atomic theory of 1803:

Each element is composed of extremely small particles called atoms
All atoms of a given element are identical; the atoms of different elements are different and have different properties (including different masses)
Atoms of an element are not changed into different types of atoms by chemical reactions; atoms are neither created nor destroyed in chemical reactions
Compounds are formed when atoms of more than one element combine; a given compound always has the same relative number and kind of atoms.

Atoms are the basic building blocks of matter; they are the smallest units of an element:

An element is composed of only one kind of atom
In compounds the atoms of two or more elements combine in definite arrangements
Mixtures do not involve the specific interactions between elements found in compounds, and the elements which comprise the mixture can be of varying ratios

	Created by ZARADOXX ALI almost 8 years ago

Slide Set on CHAPTERS SUMMARY, created by ZARADOXX ALI on 13/05/2016.