Chapter 4, Problem 41A

How did the charge distribution in the plum pudding model affect alpha particles passing through an atom?

Interpretation Introduction

Interpretation:  The affect of the charge distribution in the plum pudding model on the alpha particles passing through the atom needs to be explained.

Concept introduction:  Plum pudding model was proposed by J. J Thompson. According to this model, atom has spherical shape in which positive and negative charges are present.

Answer to Problem 41A

In plum pudding model, the charges are distributed evenly through a sphere so alpha particles passing through it are slightly deflected.

Explanation of Solution

The plum pudding model by Thompson comprised of a spherically shaped atom which is positively charged and electrons with negative charge are present in it to balance the charge.

This can be represented as follows:

The alpha particles passing through an atom of the plum pudding model are slightly deflected by positively charged protons. This is because alpha particles and protons both are positively charged.

Conclusion

Hence, alpha particles are slightly deflected only.