What determines the properties of a crystal, such as its strength, hardness, and electrical conductivity? Question 14 options: The weight of the crystal The color of the crystal The arrangement of atoms within its unit cell

To determine the properties of a crystal, such as its strength, hardness, and electrical conductivity, we need to consider the following:

1. The weight of the crystal: This is not a primary factor in determining the properties mentioned. The weight of a crystal is more related to its density and the types of atoms it contains, but it does not directly influence strength, hardness, or electrical conductivity.

2. The color of the crystal: The color is usually a result of the way the crystal interacts with light, which can be influenced by impurities or defects in the crystal structure. However, color does not directly determine the mechanical or electrical properties of the crystal.

3. The arrangement of atoms within its unit cell: This is the most critical factor. The specific arrangement of atoms within the unit cell defines the crystal structure, which in turn determines how the atoms are bonded together. This bonding affects the crystal's mechanical properties (such as strength and hardness) and its electrical properties (such as conductivity). For example, in metals, atoms are arranged in a way that allows electrons to move freely, resulting in high electrical conductivity. In contrast, in ionic crystals, the arrangement of ions can result in high hardness but low electrical conductivity.

Therefore, the correct answer is:

The arrangement of atoms within its unit cell