Chapter 4.1, Problem 3SSC

Interpretation Introduction

Interpretation:

Dalton`s atomic theory needs to be explained.

Concept introduction:

Dalton's atomic theory states that all matter is made up of atoms.

Answer to Problem 3SSC

Dalton's atomic theory proposed that all matter is made up of atoms which are indivisible in nature. According to this theory, the compounds are composed of atoms with definite ratio.

Explanation of Solution

John Dalton was aschoolteacherin British. In 1808, he has published his atomic theory. The facts of the theory were based on laws of chemical combination and other experiments.

This theory explains the law of chemical combination (the law of constant structure and the law of multiple proportions). He was the first chemist to recognize difference between an atom and compound or molecule.

Thus, according to the Dalton’s theory:

1. Matter is composed of indivisible atoms
2. For same elements, atoms are of similar mass and size but they are different for different elements.