Which term describes a naturally occurring inorganic substance with a fixed composition?

Which term describes a naturally occurring inorganic substance with a fixed composition?

• A. Migration
• B. Noble gas
• C. Natural hazard
• D. Mineral

Answer: (D)

Minerals are naturally occurring inorganic substances with a fixed chemical composition and a crystalline structure. They form through geological processes and are not produced by living things. The idea of fixed composition means each mineral has a specific chemical formula that defines what it's made of, like SiO2 for quartz, giving it a consistent identity. Some minerals can have slight variation within definite ranges, but they are still defined by particular elements and proportions, unlike substances that are organic or more variable. The other terms describe processes or categories rather than a material: migration is movement, natural hazards are risks from Earth processes, and a noble gas is a gaseous element, not a solid substance with a fixed composition.

Minerals are naturally occurring inorganic substances with a fixed chemical composition and a crystalline structure. They form through geological processes and are not produced by living things. The idea of fixed composition means each mineral has a specific chemical formula that defines what it's made of, like SiO2 for quartz, giving it a consistent identity. Some minerals can have slight variation within definite ranges, but they are still defined by particular elements and proportions, unlike substances that are organic or more variable. The other terms describe processes or categories rather than a material: migration is movement, natural hazards are risks from Earth processes, and a noble gas is a gaseous element, not a solid substance with a fixed composition.