SCI11s

• The Earth is a closed system where there is only an exchange of heat and energy but no exchange of matter
• Materials on Earth cycle between the Geosphere (land), Atmosphere (air), Hydrosphere (water), and Biosphere (living organisms)
• Isolated system does not allow matter and energy to leave or enter
• Closed system allows energy to enter and leave but does not allow matter to leave and enter
• Open system allows both energy and matter to enter and leave
• Factors that make Earth a habitable planet:

  • Temperature:
  • Earth lies in the "Goldilocks Zone" where temperature is not too cold or too hot
  • Temperature indicates the direction in which heat energy will flow
  • Atmosphere:
  • Layers of gases that surround the planet
  • Absorbs the sun's heat energy providing warmth and energy
  • Acts as a shield from harmful rays and extraterrestrial objects
  • Energy:
  • Energy from the Sun is vital for life on Earth
  • Source of energy used by humans
  • Nutrients:
  • Chemical substances found in every living thing on Earth
• • Used in every process of an organism's body
• Four subsystems of the Earth:

  1. Geosphere:

  • Contains rocks, minerals, and ground on and in Earth
  • Includes the crust, mantle, and core

  2. Atmosphere:

  • Layers of gases that surround the planet

  3. Hydrosphere:

  • Includes liquid, gaseous, and solid water on Earth
  • Consists of oceans, seas, ice, glaciers, lakes, rivers, streams, atmospheric moisture, and groundwater
  • 97% is ocean water, 3% is fresh water

  4. Biosphere:

  • Contains all living organisms on Earth
  • Living organisms form communities called biomes filled with ecosystems
• Differences between inner and outer core:

  • Outer Core:
  • Liquid layer of molten iron and nickel
  • Thickness of about 2,300 kilometers
  • Inner Core:
  • Solid, central part of the Earth
  • Radius of about 1,220 kilometers
  • Composed of solid iron and nickel
• Layers of the Earth:

  • Crust:
  • Outermost layer, thinnest
  • Continental Crust: thicker layer under continents, made mostly of granite
  • Oceanic Crust: thinner layer under oceans, made mostly of basalt
  • Mantle:
  • Layer beneath the crust, thickest layer
  • Upper Mantle: contains asthenosphere allowing movement of tectonic plates
  • Lower Mantle: solid, contributes to convection and heat transfer
  • Core:
  • Innermost layer beneath mantle
• Atmosphere layers:

  • Troposphere: where most clouds and weather occur
  • Stratosphere: where ozone layer is found
  • Mesosphere: where meteors burn up
  • Thermosphere: hottest layer, where aurora borealis form
  • Exosphere: outermost layer where satellites are stationed
• Water Cycle:

  • Drives the hydrosphere, enabling water to be recycled and moved around Earth
  • Evaporation: change from liquid to gaseous state, requires heat energy
  • Condensation: change from gaseous to liquid state
  • Precipitation: primary mechanism for transporting water to Earth's surface
  • Collection: water that did not get absorbed or evaporate
• Types of Biomes:

  • Rainforest: tropical and temperate
  • Coniferous Forest: trees with needles and cones
  • Grassland: rolling terrains of grasses and herbs
  • Desert: extremely dry environments
  • Tundra: coldest biome with frost-molded landscapes
  • Deciduous Forest: trees lose foliage at end of growing season
  • Shrublands: fire-resistant shrubs or short trees
  • Marine: world's largest biome covering three-quarters of Earth's surface
  • Freshwater: ponds, lakes, streams, rivers, vital source of drinking water
• Minerals are the "building blocks" of rocks
• Minerals are naturally occurring pure substances with a definite chemical composition
• Minerals are arranged in an orderly repeating atomic structure that defines a crystal structure
• Minerals can be either elements or compounds chemically bonded to each other
• • Halides: minerals containing halogen elements like Chlorine, Fluorine, and Iodine (e.g., Cryolite, Halite)
  • Native elements: minerals formed as individual elements (e.g., Gold, Sulfur)
  • Metals: minerals with high thermal and electrical conductivity, metallic luster, and low hardness (e.g., Gold, Silver)
  • Non-Metals: minerals with poor conductivity (e.g., Sulfur, Diamond)
  • Semi-Metals: minerals that are more fragile than metals but have lower conductivity (e.g., Arsenic, Bismuth)
• Chemical properties of minerals:

  • Silicates: minerals containing Silicon and Oxygen, over 90% of minerals in rocks belong to this group (e.g., Feldspar, Mica, Quartz)
  • Carbonates: minerals containing carbonate ion (e.g., Calcite, Dolomite)
  • Oxides: minerals containing oxygen anion bonded with other metals (e.g., Hematite, Magnetite)
  • Sulfates: minerals containing sulfur and oxygen in the form of sulfate anion (e.g., Gypsum, Barite)
  • Sulfides: minerals containing sulfur anion bonded with other elements (e.g., Galena, Pyrite)
• Physical properties of minerals:

  • Color: property used to identify minerals easily
  • Streak: describes the color of the mineral in its powdered form
  • Luster: describes how minerals' surface reflects light (Metallic Luster or Non-Metallic Luster)
  • Hardness: measure of mineral's resistance to scratching (measured by Moh's scale)
  • Cleavage: tendency of a mineral to break evenly along its weakest plane
  • Fracture: describes the mark left when a mineral breaks (Conchoidal, Uneven, Hackly/Jagged)
  • Specific Gravity: ratio of mineral density to water density
• • Magnetism: property that exhibits attraction to magnets
  • Reaction to acids: property of minerals that react with strong acids
  • Odor: property of minerals that give off distinct smells (e.g., Sulfur smells like rotten eggs)
  • Taste: property of minerals that exhibit certain tastes (e.g., Halite tastes salty)
• Rocks are solid, inorganic, naturally-formed without a particular atomic structure or chemical composition
• Rocks consist of several different minerals that are either cemented, squeezed, heated, melted, or cooled together
• Igneous rocks are formed from the cooling and solidification of magma and lava:

  • Intrusive Igneous Rocks: formed from slow-cooling magma deep inside the Earth (e.g., Diorite, Granite)
  • Extrusive Igneous Rocks: formed from quick-cooling lava above or near the Earth's surface (e.g., Obsidian, Basalt)
• Sedimentary rocks are formed by the accumulation of sediments and often have distinctive layering or bedding
• Types of sedimentary rocks:

  • Clastic Sedimentary Rocks: formed from mechanical weathering debris based on the size of sediment
  • Chemical Sedimentary Rocks: formed from dissolved minerals precipitated from a solution
  • Organic Sedimentary Rocks: formed from the accumulation of plant or animal debris
• Metamorphic rocks are formed when "parent rocks" are subjected to high heat, high pressure, or hot mineral-rich fluids:

  • Foliated Metamorphic Rocks: formed when pressure aligns minerals to appear banded or foliated
  • Non-Foliated Metamorphic Rocks: formed when heat changes the mineral structure without adding pressure
• Metamorphic rocks can be foliated or non-foliated
• Non-foliated metamorphic rocks are formed when the pre-existing rock is "baked" by heat, changing the mineral structure without pressure
• All rock types can undergo metamorphism to create metamorphic rocks
• All rock types undergo weathering and erosion to create sediments for sedimentary rocks
• All rock types exposed to extreme heat undergo melting to form magma for igneous rocks
• Mineral resources include all useful rocks and minerals, important raw materials for various industries
• All minerals are nonrenewable, but many can be recycled
• Classified as metallic minerals (e.g. iron, lead, copper) and non-metallic minerals (e.g. salt, sand)
• Terms to remember:

  • Beneficiation: process of finding a mineral deposit, extracting the resource, and recovering it
  • Ore: naturally occurring material from which minerals of economic value can be extracted
  • Mineral occurrence: concentration of a valuable mineral
  • Mineral deposit: occurrence of sufficient size and grade for extraction
  • Ore deposit: tested mineral deposit of size, grade, and accessibility for profitable mining
• Mining is the process to extract valuable non-renewable resources like mineral deposits and fossil fuels
• Types of mining:

  • Surface Mining:
  • Involves removing terrain surfaces and plant life to access minerals underneath
  • Advantages: produces ore without costly overburden removal, lowest cost
  • Disadvantages: detrimental to the environment, affects soil and biologic life quality
  • Underground Mining:
  • Involves creating tunnels and shafts to reach mineral deposits
  • Advantages: hidden operations, less damaging to the environment, produces little waste
  • Disadvantages: fatal accidents, long time to operate, high production cost
  • Placer Mining:
• • Involves sifting valuable materials from sediments in riverbeds or sands
  • Advantages: high productivity with low cost
  • Disadvantages: environmentally destructive, occurs within streambeds
  • In-Situ Mining:
  • Involves leaving ore in place and recovering minerals by pumping chemicals underground
  • Advantages: cost-effective, environmentally friendly, minimal surface disturbance
  • Disadvantages: risk of leaching liquid contamination, waste water production
• Energy resources are materials used as a basis for generating power

  • Non-renewable resources are limited in supply and include coal, oil, and natural gas
  • Fossil fuels release energy when burned