Chapter 17, Problem 29A

To determine

The four phases of matter.

Answer to Problem 29A

The four phases of matter are solid, liquid, gas and plasma.

Explanation of Solution

Introduction:

Based on the molecular structure of matter it can be considered to exist in four different phases depending on the temperature and the pressure level. Each phase shows distinct features and hence can be differentiated from one another. Also, the forces existing between the molecules in the matter differ from each other based on its phase.

The four different phases of matter are discussed considering water and its forms as an example.

1) Solid −In this phase, the molecules of the matter are tightly held together to form a rigid structure. There is no free movement of molecules and only vibration is possible. Due to their molecular feature, they are able to form a definite shape and can occupy a fixed volume.

Ice is an example for this phase of matter.

2) Liquid- When, some energy is provided to a matter in its solid state such as ice, it results in breaking the molecular structure of the ice and converts it to water which is liquid state. Here, the H₂ O molecules are free to move compared to the solid.

3) Gaseous phase- When some energy is provided to a matter in liquid phase, it further breaks down the molecules and sets them free to form a gaseous state. Vapor is an example for this when considering the gaseous phase of water.

4) Plasma- This is the state where, the ions and electrons are formed by adding energy to gaseous matter. The molecular forces are very weak in this state.