Chapter 4, Problem 32A

Interpretation Introduction

Interpretation:

The atomic theories proposed by Democritus and John Dalton are to be distinguished.

Concept introduction:

Atomic theories state that all the matter is composed of atoms that are composed of protons, neutrons and electrons.

Explanation of Solution

Difference between the two theories is as follows:

Democritus’ Atomic Theory	Dalton’s Atomic Theory
Atoms move in an empty space that is made of matter. They are indivisible, solid and homogenous and indestructible.	Matter is made up of small particles called atoms. Atom can neither be created nor be destroyed or divided into further smaller particles.
Different atoms have different sizes and shapes.	Atoms of each element have same size, mass and chemical properties.
The size and shape of different atoms gives the unique properties of matter.	Different atoms come together in whole numbers and form compounds.
The changes in matter are a result of changes in the grouping of the atoms and not the changes in the atom it self.	Chemical reactions cause atoms to separate from each other or to combine.