Below is an example of an original passage from a chemistry textbook.  Create a spoken version of this passage.
 
Original passage:
Matter can undergo changes of two basic types: physical changes and chemical changes. Physical changes are processes in which a material changes its physical appearance but not its basic identity. The evaporation of water is a physical change. When water evaporates, it changes from the liquid state to the gas state, but it is still water; it has not changed into any other substance. All changes of state are physical changes. In chemical changes, also called chemical reactions, substances change not only in physical appearance but also in basic identity; that is, one substance is converted into another. For example, hydrogen burning in air undergoes a chemical change in which it is converted to water.

Spoken version:
Good morning! Today, I would like to talk about changes in matter. Matter can undergo changes of two basic types. These two types of changes are physical and chemical changes.

First, let's discuss physical changes. Does anyone have an idea of what physical changes are? (Respond to answers). Physcial changes are processes in which a material changes only its physical appearance. This means that the basic identity of the material stays the same. One example of a physical change is the evaporation of water. When water evaporates, it changes from a liquid state to a gas state. But, it is still water. It doesn't experience changes in its basic identity. In other words, its boilling point, vapor pressure, density, and molecular weight stay the same. The water has not changed into any other substance. Can anyone think of any other examples of a physical change? (Respond to answers). So, to summarize, all changes of state are physical changes.

Now let's talk about the other type of changes in matter--chemical changes. During chemical changes, also called chemical reactions, substances will experience changes in their basic identity in addition to changes in physical appearance. This means that one substance is converted into another substance, and this new substance has different characteristics. For example, hydrogen burning in air will convert into water. Therefore, hydrogen burning in air involves physical and chemical changes. The physical change is the change from the gas state to the liquid state whereas the chemical changes is the change of the substance from hydrogen to water. Can anyone think of another example of a physical change? (Respond to answers).

To summarize, matter can undergo physical and chemical changes. In chemical changes, substances experience changes in both their physical appearance and basic identity, whereas in physcial changes, substances only experience changes in their physical appearance. I hope that's clear to everyone. Are there any questions?