Chemistry Terms: A Brief Chemical Composition

Key Terms:

Mineral- a naturally occurring, inorganic solid that has a crustal structure and a definite chemical composition

Rock- a large mass of stone

Organic- derived from living organisms

Inorganic- not derived from living organisms

Pure Substance- a form of matter that has a constant chemical composition and characteristic properties. It cannot be separated into its several components without breaking its chemical bonds.

Element- a substance composed of a single kind of atom

Molecule- the smallest physical unit of an element or compound, consisting of one or more like atoms in a element and two of more different atoms in a compound

Compound- a substance in which two or more elements are chemically joined

Mixture- any combination or blend of different elements, kinds, qualities, etc

Solution- a mixture in which one substance is dissolved in another

Mohs Scale- a scale ranking ten minerals from softest to hardest;
used in testing the hardness of minerals

Streak- the color of a mineral’s powder

Luster- the way a mineral reflects light from it’s surface

Cleavage- a minerals ability to split easily along flat surfaces

Fracture- the way a mineral looks when it breaks apart in an irregular way

Vein- a narrow slab of mineral that is sharply different from the surrounding rock

Gemstone- a hard, colorful mineral that has a brilliant or glassy luster

Ore- rock that contains a mineral or economically useful mineral

Smelting- the process in which ore in melted to separate the useful metal from other elements

Alloy- a solid mixture of two or more minerals

Learning Targets:

Identify the characteristics of a mineral: Naturally occurring, inorganic, crystal structure, solid, and definite chemical composition.
Describe the properties of minerals: hardness, color, streak, crystal systems, cleavage, fracture, luster, and density

Explain how minerals are identified: Each mineral has its own specific properties that can be used to identify it

Distinguish the difference between general and specific properties: Physical properties are things like the weight, mass, density, or volume. General properties are things that can change, like color or texture.

Describe the processes by which minerals form: there are two processes that form minerals. They are crystallization of melted materials, and through crystallization of materials dissolved in
water.

Describe how minerals are used: Gemstones are used mainly for jewelry and decoration. They are also used for mechanical parts and for grinding and polishing. Metals can be stretched into wire, flattened into sheets, and hammered or molded without breaking. Metals are used in tools and machinery, the metal filament in a light bulb, even the steel girders used to frame office buildings. There are also other useful minerals that are used in food, medicines, fertilizers, and building materials.

List the three types of mines: Strip mines, open pit mines, and shaft mines