Chapter 2 Minerals Wordwise Answer Key

Chapter 2: Minerals - WordWise Answer Key: A Comprehensive Guide

This article provides a comprehensive guide and answer key for Chapter 2: Minerals, likely from a geology or earth science textbook. Since I don't have access to specific textbooks, I will offer a generalized answer key covering common topics found in a chapter on minerals. This will be structured to mimic a textbook chapter, helping students understand the concepts and providing thorough answers. Remember to always cross-reference this information with your specific textbook.

Understanding Minerals: Key Definitions and Concepts

Before diving into the answer key, let's review some fundamental mineral concepts crucial for understanding the chapter.

What is a Mineral?

A mineral is a naturally occurring, inorganic, solid substance with a definite chemical composition and an ordered atomic arrangement (crystalline structure). This definition is crucial. Let's break it down:

• Naturally Occurring: Minerals are formed by natural geological processes, not synthesized in a lab.
• Inorganic: They are not produced by living organisms.
• Solid: They maintain a rigid structure at standard temperatures and pressures.
• Definite Chemical Composition: While slight variations can occur, minerals generally have a specific chemical formula (e.g., quartz - SiO₂).
• Ordered Atomic Arrangement (Crystalline Structure): Atoms are arranged in a highly ordered, repeating pattern.

Key Properties of Minerals

Identifying minerals relies on observing their physical properties. These properties often relate directly to their chemical composition and crystal structure. Important properties include:

• Hardness: Resistance to scratching, measured on the Mohs Hardness Scale.
• Cleavage: The tendency of a mineral to break along planes of weakness.
• Fracture: How a mineral breaks when it doesn't cleave.
• Luster: The way a mineral reflects light (e.g., metallic, vitreous).
• Color: Can be diagnostic for some minerals but unreliable for many.
• Streak: The color of a mineral's powder.
• Density: Mass per unit volume.
• Crystal Habit: The characteristic shape of a mineral crystal.
• Special Properties: Some minerals exhibit unique properties like magnetism, fluorescence, or radioactivity.

Chapter 2: Minerals - WordWise Answer Key (Sample Questions & Answers)

This section provides sample questions and answers that would typically be found in a "WordWise" or vocabulary section of a Chapter 2 Minerals textbook. The specific questions will vary by textbook, but these examples cover important mineral terminology.

Section 1: Mineral Definitions

1. Define the term "mineral."

Answer: A mineral is a naturally occurring, inorganic, solid substance with a definite chemical composition and an ordered atomic arrangement (crystalline structure).

2. What is the difference between a rock and a mineral?

Answer: A mineral is a naturally occurring, inorganic solid with a definite chemical composition and crystalline structure. A rock is a naturally occurring solid aggregate of one or more minerals. Rocks are composed of minerals.

3. Explain the significance of crystalline structure in defining a mineral.

Answer: The ordered atomic arrangement, or crystalline structure, is essential because it distinguishes minerals from amorphous solids (solids without a regular atomic arrangement). The repeating pattern of atoms determines many of the mineral's physical properties.

4. What does "inorganic" mean in the context of mineral definition? Provide an example of a substance that is not considered a mineral due to this property.

Answer: Inorganic means not derived from living organisms. Coal, for example, is formed from the remains of plants and therefore is considered an organic substance and not a mineral.

5. What is a polymorph? Give an example.

Answer: Polymorphs are minerals that have the same chemical composition but different crystal structures. Diamond and graphite are both made of carbon (C) but have different crystal structures leading to vastly different properties.

Section 2: Mineral Properties

1. Explain the Mohs Hardness Scale.

Answer: The Mohs Hardness Scale is a relative scale of mineral hardness. It ranks minerals from 1 (talc, the softest) to 10 (diamond, the hardest) based on their resistance to being scratched. A mineral can scratch any mineral with a lower hardness number.

2. Describe the difference between cleavage and fracture.

Answer: Cleavage refers to the tendency of a mineral to break along planes of weakness in its crystal structure, resulting in flat, smooth surfaces. Fracture describes the way a mineral breaks when it doesn't cleave, producing irregular, rough surfaces.

3. What is luster? Name two types of luster.

Answer: Luster refers to the way a mineral reflects light. Two common types are metallic luster (shiny like a metal) and vitreous luster (glassy).

4. Why is color often an unreliable indicator of mineral identity?

Answer: Color can be highly variable in many minerals due to trace impurities or slight changes in chemical composition. The same mineral can appear in various colors.

5. What is streak? How is it determined?

Answer: Streak is the color of a mineral's powder. It is determined by scratching the mineral across a piece of unglazed porcelain (streak plate). Streak is often more reliable than color for mineral identification.

Section 3: Mineral Groups & Formation

1. What are silicate minerals? Why are they the most abundant mineral group in the Earth's crust?

Answer: Silicate minerals are minerals containing silicon and oxygen, the two most abundant elements in the Earth's crust. Their abundance stems from the abundance of these elements. They form the building blocks of most rocks.

2. Briefly describe three different ways minerals can form.

Answer: Minerals can form through: * Crystallization from magma or lava: As molten rock cools, minerals crystallize. * Precipitation from solution: Minerals form when dissolved substances in water precipitate out of solution. * Metamorphism: Existing rocks are changed by heat and pressure to form new minerals.

3. What is a mineral resource?

Answer: A mineral resource is a naturally occurring concentration of minerals that can be extracted economically.

4. What is the difference between a renewable and non-renewable resource? Give examples related to minerals.

Answer: Renewable resources can be replenished naturally over a relatively short time span (e.g., sunlight, wind). Non-renewable resources are formed over geological timescales and are consumed much faster than they can be replaced (e.g., most minerals and fossil fuels).

5. What are some of the environmental impacts of mineral extraction?

Answer: Mineral extraction can have several significant environmental impacts, including habitat destruction, water pollution, air pollution, soil erosion, and the generation of waste materials.

Beyond the WordWise: Expanding Your Knowledge

This comprehensive guide goes beyond a simple answer key. It encourages deeper understanding by exploring related concepts. To further enhance your comprehension of Chapter 2: Minerals, consider these points:

• Mineral Identification Charts: Practice identifying minerals using charts that show key properties.
• Rock-Forming Minerals: Learn about the major rock-forming minerals and their role in creating various rock types.
• Economic Geology: Investigate the economic importance of minerals and their uses in society.
• Mineral Exploration and Mining: Understand the processes involved in finding and extracting mineral resources.
• Sustainability in Mineral Resource Management: Research sustainable practices for minimizing the environmental impacts of mining.

By actively engaging with these concepts and expanding your research beyond the basic "WordWise" section, you'll gain a much stronger grasp of mineralogy and its significance in Earth science. Remember to always consult your specific textbook for the most accurate and relevant information.