Chapter 11.17, Problem 1QP

To determine

The two stages involved in the formation of particles of a new phase.

Answer to Problem 1QP

The brief description of two stages involved in the formation of particles of a new phase is explained below.

Explanation of Solution

The two stages involved in the formation of particles of a new phase are:

• Nucleation
• Growth

Nucleation:

The development of very miniature nuclei of a new phase from the parent phase, similar to embryo is known as nucleation. There are two types of nucleation, heterogeneous and homogeneous nucleation.

In heterogeneous nucleation, nuclei produce at non-homogeneous structures, like surface of container, boundaries of grain and so on.

In homogeneous nucleation, nuclei or particles produce within parent phase.

Growth:

The growing phase of the particle is called as growth. In this phase, the particles transform into a stable nucleus and the size of embryo got bigger than the decisive shape. The process of growth forms a new phase nuclei within the parent phase. The process of growing continues till the new formed nuclei got stable and replace the parent nuclei.