Which of the following is not a characteristic of a crystal?
a. The arrangement of the atoms in a crystal determines its shapes.
b. A crystalline structure is always geometric.
c. Crystals are classified according to their mineral content.
http://en.wikipedia.org/wiki/Crystal
To determine which of the following is not a characteristic of a crystal, let's look at each option:
a. The arrangement of the atoms in a crystal determines its shapes.
This statement is true. The arrangement of atoms in a crystal determines its characteristic shapes. Crystals have a repeating pattern of atoms that forms a specific shape.
b. A crystalline structure is always geometric.
This statement is also true. Crystalline structures always have a regular and repeating geometric pattern. This is one of the defining characteristics of crystals.
c. Crystals are classified according to their mineral content.
This statement is not entirely accurate. Crystals are not classified solely based on their mineral content. While the mineral content can be a factor in classification, crystals are primarily classified based on their structure and arrangement of atoms.
Therefore, the correct answer is c. Crystals are not solely classified based on their mineral content.