Chapter 3.3, Problem 1RQ

Interpretation Introduction

Interpretation:Difference between Thomson’s and Dalton’s atomic theory needs to be explained.

Concept introduction: Theory is a group of connected ideas or concepts intended to describe something.  It involves question- “why” or “how anything/ somethings happens. It is based on inference.

Answer to Problem 1RQ

Dalton’s atomic theory was proposed by John Dalton. According to the Dalton’s atomic theory, matter is composed of tiny particles, all atoms of certain element are identical, compound contains more than one element. In J.J. Thomson’s atomic theory, electrons are distributed inside a positive mass like raising in a plum pudding.

Explanation of Solution

Scientist John Dalton and Scientist JJ Thompson proposed different models of an atom.Difference between Thomson’s atomic theoryand Dalton’s atomic theory is mentioned below:

Thomson’s atomic theory	Dalton’s atomic theory
Thomson’s model of the atom includes electrons in a plum pudding model.	Dalton’s model does not and is more of a solid sphere.
Tiny negative electrons were distributed in a positive (+ve) mass inside the atom. The electrons were like negative (-ve) raising in a positive(+ve) plum pudding dough.	Atoms were tiny, hard spheres that vary in size as well as mass, but can’t be split into smaller pieces.
Picture of plum pudding model proposed by JJ Thompson:	Picture of solid sphere model proposed by the scientist John Dalton:

Conclusion

Thomson’s atomic theoryand Dalton’s atomic theory are not the same.