Which one of the following is NOT true for minerals?
They have a specific, internal, crystalline structure.
They can be a solid, liquid.
They have a specific predictable chemical composition.
They can be identified by characteristic physical properties.
The Correct Answer And Eplanation is:
Correct Answer: They can be a solid, liquid.
Explanation:
Minerals are naturally occurring, inorganic substances with a definite chemical composition and an ordered internal crystalline structure. This means each mineral is composed of specific elements arranged in a repeating geometric pattern at the atomic level. These atomic arrangements give minerals their unique crystalline structure, which is essential for classifying them.
Now, let’s analyze the given statements:
- “They have a specific, internal, crystalline structure.”
✅ True. This is one of the defining characteristics of minerals. Their atoms are arranged in an orderly, repeating pattern. For example, quartz has a consistent crystal structure made of silicon and oxygen atoms in a specific configuration. - “They can be a solid, liquid.”
❌ Not true. Minerals are always solid under normal Earth conditions. Liquids, like water or molten rock (magma), do not have a fixed crystalline structure and thus cannot be classified as minerals. While ice (solid water) can be a mineral because it forms a crystalline structure, liquid water is not a mineral. This statement is the only incorrect one in the list. - “They have a specific predictable chemical composition.”
✅ True. Minerals have a definite chemical formula that can vary within a limited range. For instance, the mineral olivine can range in composition from (Mg,Fe)₂SiO₄, but the variation is still predictable and within a known range. - “They can be identified by characteristic physical properties.”
✅ True. Minerals can be identified using various physical characteristics such as color, luster, hardness (Mohs scale), cleavage, fracture, and streak. These properties result from the mineral’s internal atomic structure and chemical composition.
In summary, minerals are solid, naturally occurring substances with a crystal structure and defined chemistry. They are never liquids, which makes that option the correct answer as it is not true for minerals.