Pearson Chapter 2

2.1

Atom: Comes from the Greek atomos. Meaning indivisible.

Brownian motion: The particle motion was the result of molecular bombardments of the particles due to the thermal energy of the surrounding water.

STM: Scanning tunneling microscope.

STMs can pick up and move individual atoms

An atom is the smallest identifiable unit of an element.

91 naturally occurring elements

Scientists have made over 20 synthetic elements.

First proposal of small indestructible particles were Leucippus and Democritus.

Copernicus and his book on the earth revolving the sun started the scientific revolution.

Atomic Theory:

Law of conservation of mass & Law of definite proportions helped pave the way for atomic theory.

1. Each element is composed of tiny, indestructible particles called atoms.

2. All atoms of a given element have the same mass and other properties that distinguish them from the atoms of other elements.

3. Atoms combine in simple, whole-number ratios to form compounds.

4. Atoms of one element cannot change into atoms of another element. In a chemical reaction, atoms only change the wat that they are bound together with other atoms.