Question

The ability of a substances to assume two or more crystalline structures is called: (a) Amorphism (b) Diamondl (c) Graphite (d) None

Short answer

(d) None

Step-by-step solution

Identify the Key Concept

The question is about a material's ability to have multiple crystalline structures. This is a well-known concept in material science.

Recall the Term

The term that describes the ability of a substance to exist in more than one crystalline form is 'polymorphism'. Though not explicitly listed, the correct option involves understanding that none of the listed options directly refer to this concept.

Evaluate Each Option

(a) Amorphism refers to structures lacking a defined form, so it's incorrect. (b) Diamond and (c) Graphite are forms of carbon but do not define the concept asked. (d) None indicates that none of the given options correctly refer to polymorphism.

Choose the Right Answer

Since none of the options accurately define a substance's ability to form multiple crystalline structures, the correct answer is (d) None.

Key concepts

Crystalline structures

Crystalline structures are the ordered arrangements of atoms or molecules in a solid material. In these structures, the atoms are organized in a repetitive pattern that extends in all three spatial dimensions. This ordered pattern is what gives crystalline materials their distinct physical properties, like their ability to fracture along specific planes, known as cleavage lines. In everyday life, we observe these structures in materials such as salt, diamonds, and metals.

Crystalline materials often have high symmetry, which contributes to their unique optical and mechanical properties. The precise nature of the crystalline structure can influence how a material behaves, including its strength, hardness, and melting point. Understanding these structures allows scientists to predict and manipulate the properties of materials for different applications in industry and technology.

Material science

Material science is a field that explores the properties of different materials and how they can be used in practical applications. It's a discipline that combines elements of physics, chemistry, and engineering to study the relationships between the structure of materials and their properties. This understanding helps scientists develop new materials with desired traits for specific uses, such as stronger metals, more efficient electronics, or durable plastics.

In material science, polymorphism is a critical concept. This phenomenon occurs when a material can exist in more than one crystalline form, leading to different physical properties. Polymorphism is significant in pharmaceuticals, where the crystalline form of a drug can affect its solubility and bioavailability. Material scientists study these forms to optimize and enhance material performance in various applications.

Amorphism

Amorphism refers to the property of a material that lacks a defined crystalline structure. Unlike crystalline materials, amorphous substances do not display a long-range order. Instead, their atomic or molecular arrangements are more randomly organized. Common examples of amorphous materials include glass, gels, and certain plastics.

Amorphous materials are often characterized by their isotropy, meaning they have the same properties in all directions. This is unlike crystalline materials, which can behave differently depending on direction due to their ordered structure. Amorphous substances are generally softer, more flexible, and have lower melting points compared to their crystalline counterparts, making them suitable for specific applications like optical materials and flexible electronics.

Carbon forms

Carbon is a unique element that can appear in different forms, known as allotropes. This diversity is due to carbon's ability to form stable bonds with itself and with other elements. The most well-known forms of carbon include diamond and graphite, which demonstrate distinct crystalline structures.

Diamond is renowned for its hardness and clarity, resulting from each carbon atom forming four strong covalent bonds in a tetrahedral structure. In contrast, graphite is composed of layers where carbon atoms are arranged in hexagonal arrays, allowing the layers to slide easily over one another, making graphite a good lubricant.

• Diamond: Extremely hard, optically clear, tetrahedral lattice
• Graphite: Conductive, soft, layered hexagonal lattice

These forms illustrate the concept of polymorphism, showcasing how the same element can exhibit vastly different properties based on its structural arrangement.