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Starter:. What is the density of a cube with a side length of 3 cm and a mass of 27 grams?. Starter:. What is the density of a cube with a side length of 3 cm and a mass of 27 grams? length = 3 cm, lxwxh = Volume, which equals? Mass = 3 grams. Starter:.
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Starter: • What is the density of a cube with a side length of 3 cm and a mass of 27 grams?
Starter: • What is the density of a cube with a side length of 3 cm and a mass of 27 grams? • length = 3 cm, lxwxh = Volume, which equals? • Mass = 3 grams
Starter: • What is the density of a cube with a side length of 3 cm and a mass of 27 grams? • length = 3 cm, lxwxh = Volume, which equals 27 cm³ • Mass = 27 grams • Density = mass divided by volume = 1 g/cm³
Minerals Practice notes
Minerals: From the Inside Out • Minerals are the building blocks that make up rocks • There are about 3000 known minerals.
Answer These Questions • To be a mineral, all of the following questions must be answered “yes”: • Is it nonliving material? A mineral is inorganic. • Is it formed in nature? Only naturally made crystals are classified as minerals. • Does it have a crystalline structure (repeating inner structure that determines shape)? • Is it a solid? No gases or liquids allowed.
Two Groups of Minerals • Minerals are divided into two groups based on chemical makeup: • Silicate minerals – contain silicon & oxygen, with additional elements; make up more than 90% of Earth’s crust. • Nonsilicate minerals - no silicon or oxygen but C, O, Fe, S (carbonates – calcite, halides – fluorite, oxides – corundum, sulfates - gypsum
Silicate Minerals Quartz Feldspar Mica All silicate minerals contain the elements silicon and oxygen.
Nonsilicate Minerals CALCITE FLUORITE
Nonsilicate Minerals CORUNDUM GYPSUM
Identifying Minerals • 1. Color • Impurities can change color (quartz vs. amethyst) • Air and water can also change color of mineral (pyrite is golden, but exposure turns it black)
Color Quartz and amethyst are both silicon dioxide (SiO₂) but amethyst contains impurities which gives it its purple color.
Identifying Minerals (cont.) • 2. Luster • How the surface of a mineral reflects light. • Controlled by how atoms are bonded • Metallic, submetallic, nonmetallic (vitreous, silky, resinous, waxy, pearly, earthy)
Identifying Minerals (cont.) • 3. Streak • Color of mineral in powdered form • Not always the same color of mineral sample • More reliable than color of mineral Hematite may vary in color but the streak will always be reddish brown.
Identifying Minerals (cont.) • Cleavage and Fracture • How mineral breaks, determined by atomic arrangement • 4. Cleavage– tendency to break along flat surfaces (mica, halite) because bonding is weakest in those directions. • 5. Fracture – tendency to break along curved or irregular surfaces (quartz – conchoidal) when bonding is equally strong in all directions.
Identifying Minerals (cont.) • 6. Hardness • Resistance to being scratched • Mohs hardness scale: Talc, Gypsum, Calcite, Fluorite, Apatite, Orthoclase, Quartz, Topaz, Corundum, Diamond
Hardness Scratch Test • < 2.5 = Mineral marks paper • 2.5 = Fingernail • 3 = Copper Penny • 5 = Steel knife blade • 6 = Plate of glass • 6.5 = Steel file
Identifying Minerals (cont.) • 7. Density • How much matter there is in a given amount of space (D = m/v) (g/ cm³)
Identifying Minerals (cont.) • 8. Special Properties • Fluorescence (calcite, fluorite glow under UV) • Chemical reactions (calcite) • Optical – calcite causes double images • Taste – halite • Magnetism – magnetic, pyrrhotite attract iron • Radioactivity – minerals containing radium or uranium can be detected with a Geiger counter.
Elements and compounds Element- A substance that cannot be broken into simpler substances by chemical means. Found on the periodic table. Compound- A substance made of two or more different atoms that are chemically bonded.
Application: • Vocabulary foldable
Connection: Lab • Exit: in 3-5 sentences How would you describe the mineral that represents your birthday month, using the vocabulary from today’s lesson?