2.12. Solids http://www.ck12.org
FIGURE 2.21
Amorphous means “shapeless.” Particles of amorphous solids are arranged more-or-less at random and do not form
crystals, as you can see in theFigure2.22. An example of an amorphous solid is cotton candy, also shown in the
Figure2.22.
FIGURE 2.22
Q:Look at the quartz rock and plastic bag pictured in theFigure2.23. Which type of solid do you think each of
them is?
A:The quartz is a crystalline solid. Rocks are made of minerals and minerals form crystals. You can see their
geometric shapes. The bag is an amorphous solid. It is made of the plastic and most plastics do not form crystals.
Summary
- A solid is a state of matter in which particles of matter are tightly packed together. This holds the particles
rigidly in place and gives solids a fixed shape and fixed volume. - Crystalline solids have particles that are arranged in a regular repeating pattern. They form crystals. Amor-
phous solids have particles that are arranged more-or-less at random. They do not form crystals.