Atoms, Minerals, Rocks and Soil SJCHS

Compounds Compounds: 2+ atoms bonded together Chemical formula: states the elements in a compound and the number Example: Water: 2 Hydrogen, 1 Oxygen Glucose: 6 Carbon, 12 Hydrogen, 6 Oxygen Salt: 1 Sodium, 1 Chlorine NaCl C 6 H 12 O 6 H2OH2O

Compounds Ionic Bond: Charged atoms electrically attracted to each other

Compounds Covalent Bond: Atoms share electrons

Compounds Organic Compound: Contains 2 or more carbon Inorganic Compound: Has less than 2 carbon

Mineral Minerals: The building blocks of rocks

Mineral Mineral: Naturally occurring: Not synthetic (made in factory or laboratory)

Mineral Mineral: Usually inorganic

Mineral Mineral: Specific Chemical Composition: Minerals have a specific chemical formula Silicate minerals: Contains Silicon and Oxygen Compounds Nonsilicate minerals: No Silicon and Oxygen Compounds Pyrite: FeS 2 Quartz: SiO 2

Mineral Mineral: Crystal: A solid whose atoms or compounds are arranged in a repeating pattern Salt crystal: NaCl

Conflict Minerals Diamond Factory al-diamonds.html

Rock Rock: More than one mineral bonded together Rocks change into other types by the rock cycle (long process)

Rock Cycle Igneous Forms when magma solidifies

Rock Cycle Metamorphic Forms when rocks change due to heating and extreme pressure

Rock Cycle Sedimentary Forms when: Rocks uplifted from underneath surface of Earth, weathered (broken down)/eroded (transported away) into sediments Lithification of Sediment (rock pieces joined together)

Rock cycle review video cycle-13527/

Soil Soil: Mixture of weathered/eroded rocks, minerals, nutrients, organic matter, water, air, and organisms

Soil Horizons: Soil layers O: Litter- organic matter, organisms A: Topsoil-decomposed organic matter, organisms, nutrients and minerals for plant B: Subsoil- Inorganic matter, minerals C: Parent Material- Rock that was originally weathered to make soil Different climates have different combinations of horizons

Soil Texture: Percentage of different size particles by mass Clay: less than mm- sticky Silt: mm- floury Sand: mm- gritty

Soil Texture determines: plasticity (change of shape) water and nutrient retention Loam: Best for growing most plants

30% clay, 15% silt, 55% sand

60% clay, 20% silt, 20% sand

15% clay, 40% silt, 45% sand

30% clay, 60% silt, 10% sand

Soil Soil color can indicate chemical makeup Dark brown/ brown-red- Organic chemicals Red/Yellow- Iron White/Gray- Minerals

Soil Soil erosion and degradation is a problem for agriculture Caused by overgrazing, deforestation, addition of chemicals Desertification: Top soil is lost, land is dried

Desertification in Africa