Earth Science- Final exam studying (accumulative)

Units 4, 5, 7(Units 1, 2, 3 will be added later)

Atomic Number

Number of protons in an atom’s nucleus;defines the element. For example, all carbon atoms have 6 protons, so carbon’s atomic number is 6.

Mass number

Total number of protons+neutrons in the nucleus. This number helps identify different isotopes of the same element.

Neutrons(formula)

Mass number minus atomic number=number of neutrons. For example, if an atom has a mass number of 12 and atomic number of 6, it has 6 neutrons.

Protons

Positively charged particles found in the nucleus. They determine an atom’s chemical properties and bonding behaviour.

Neutrons

Neutral particles found in the nucleus. They contribute to the mass of an atom but don’t affect its charge.

Electrons

Negatively charged particles found in the outer electron cloud. They determine an atom’s chemical properties and bonding behavior.

Ion

Atom that has gained or lost electrons. An atom that loses electrons becomes a positive ion(cation), while an atom that gain electrons becomes a negative ion(anion). For example, sodium(Na) loses one electron to become Na+, and chlorine(Cl) gains one electron to become Cl-.

Ionic bond

bond formed when one atom transfers electrons to another. These bonds typically occur between metals and nonmetals. Example: sodium chloride(NaCl), where sodium transfers an electron to chlorine.

Covalent Bond

Bond formed when atoms share electrons. These bonds typically occur between nonmetals. Example: water(H2O), where hydrogen and oxygen atoms share electrons.

Mineral

Naturally occuring, inorganic solid with a definite chemical composition and crystal structure. All minerals must meet these four criteria to be classified as true minerals.

Streak

Colour of a mineral’s poweder when scratched across a ceramic tile. Streak is more reliable than color for mineral identification because it doesn’t change with weathering or impurities.

Luster

How a mineral reflects light. Classified as either metallic(shiny, like metal) or non-metalic (dull, waxy, glassy, etc)

Hardness(mohs scale)

Resistance to scratching. Measured by the mohs hardness scale, which ranks minerals from 1(softest) to 10(hardest).

Mohs hardness scale

Scale from 1-10 used to identify minerals. Key reference points

• Fingernail=2.5

• Copper penny=3

• Glass=5.5

  • Steel file=6.5

Cleavage

Mineral breaks along flat, smooth planes following its crystal structure. This is a predictable breaking pattern.

Fracture

Mineral breaks unevenly with no flat surfaces. This occurs when a mineral breaks in a random direction, not along its natural planes.

Density

Mass divided by volume, expressed as D=M/V. Measured in g/ml or g/cm³. For example, a mineral with a mass of 10 grams and a volume of 2cm³ has a density of 5g/cm³.

Water discplacement

Method to find the volume of irregular objects. Volume=final water level-initial water level. This method works because water fills all the spaces around an irregular object.

Igneous Rock

Formed from cooling and solidification of magma or lava. These rocks make up much of earth’s crust and mantle.

Sedimentary rock

Formed from compaction and cementation of sediments(fragments of other rocks and minerals). These rocks often contain fossils.

Metamorphic rock

Formed when existing rocks are changed by heat and/or pressure. The original rock(parent rock) is transformed without melting.

Magma

Molten rock found underground. When magma reaches earth’s surface, it becomes lava.

Lava

Molten rock that reaches earth’s surface. Lava cools to form extrusive igneous rocks.

Plutonic(intrusive) igneous rock

Forms underground from slow-cooling magma. Slow cooling allows large crystals to form. Example:Granite

Volcanic(extrusive) Igneous rock

Forms above ground from fast-cooling lava. Fast cooling results in small crystals or a glassy texture. Example:Basalt.

Felsic

Light colored igneous rock composition with high silica content. Examples: Granite, Rhyolite. These rocks are less dense and form continental crust.

Mafic

Dark-colored igneous rock composition with high iron and magnesium content. Examples: Basalt, Gabbro. These rocks are less dense and form oceanic crust.

Intermediate

Igneous rock composition between felsic and mafic. Examples: Andesite, diorite.

Bowen’s reaction series

The order in which minerals crystallize from cooling magma. This series shows that different minerals solidify at different temperatures as magma cools.

Clastic Sedimentary rock

Formed from fragments(clasts) or pieces of other rocks. These rocks are classified by clast size: clay, silt, sand, and gravel.

Chemical sedimentary rock

Formed from minerals precipitated from solution. Example: rock salt, which formed when saltwater evaporates.

Organic sedimentary rock

Formed from the remians of living organisms. Examples:Coal(from plant material) and Limestone(from shells and skeletons).

Coal formation sequence

The stages of coal development: peat, lignite, bituminous, anthracite. Each stage represents increasing pressure, heat, and carbon content.

Porosity

The percentage of open space(pores) in a rock. Higher porosity means more space for water storage.

Permeability

The ability of water to flow through connected pores in a rock. A rock can be porous but not permeable if it’s pores are not connected.

Aquifer

A permeable rock layer that holds and transmits groundwater. Aquifers are essential sources of freshwater.

Cap rock

An impermeable rock layer that traps water or oil beneath it. Cap rocks prevents groundwater and oil from rising to the surface.

Regional metamorphism

Caused by large scale heat and pressure, typically during mountain building. Produces foliated rocks with visible mineral alignment.

Contact metamorphism

Caused by heat alone from nearby magma. Produces non-foliated rocks because pressure is minimal.

Foliation

Parallel alignment of minerals in metamorphic rocks, creating visible bands or stripes. Examples: Slate, Schist, Gneiss.

Parent Rock Pairs

Shows how rocks transform through metamorphism.

Examples of parent rock pairs:

Sandstone=Quartzite, Limestone=marble, Shale= slate, phyllite, schist, gneiss.

Continental drift

Wegener’s hypothesis that continents were once joined together and have drifted over geological time. This theory explained why continents fit together like puzzle pieces and had similar fossils.

Pangea

The supercontinent that existed approximately 200 million years ago. All continents were joined as one massive landmass before breaking apart.

Plate tectonics

The theory explaining the movement of earth’s lithospheric plates. This theory combines continental drift with the mechanism of how plates move.

Lithosphere

The rigid outer layer of earth that includes the crust and upper mantle. The lithosphere is broken into large pieces called tectonic plates.

Asthenosphere

The semi-molten layer below the lithosphere. Tectonic plates float and move on this layer due to convection currents in the mantle.

Convergent boundary

Plates move toward each other. This boundary type forms mountains, deep ocean trenches, and volcanoes. Example: The collision of the indian and eurasian plates forming the Himalayas.

Divergent boundary

Plates move apart from each other. This boundary type forms mid ocean-ridges and rift valleys. Example: The mid-atlantic ridge, where the north american and eurasian plates separate.

Transform Boundary

Plates slide past each other horizontally. This boundary type forms faults and causes earthquakes. Example: The san andreas fault in California.

Subduction

When a denser oceanic plate sinks beneath a less dense continental plate at a convergent boundary. This process recycles oceanic crust back into the mantle.

Seafloor spreading

The process where new oceanic crust forms at mid-ocean ridges as plates diverge. Magma rises from the mantle, cools, and solidifies to create new crust.

Focus(hypocenter)

The point underground where an earthquake originates. This is where energy is released as rock breaks or shifts.

Epicenter

The point on earth’s surface directly above the focus. This is usually where the most damage occurs.

P-waves(primary)

The fastest seismic waves. They travel through both solids and liquids and have a compressional(push-pull) motion. P-waves arrive at seismograph stations first.

S-waves(secondary)

Slower than P-waves. They travel only through solids and have a shear(side-to-side) motion. S-waves arrive after P-waves.

L-waves(surface)

The slowest seismic waves. They travel along earth’s surface and cause the most damage because they large amplitudes.

Seismograph

An instrument that detects and records seismic waves from earthquakes.

Seismogram

The actual paper record or printout produced by a seismograph. It shows the arrival times and amplitudes of different seismic waves.

S-P time lag

The difference in arrival time between P-waves and S-waves at a seismograph station. This time lag is used to calculate the distance from the station to the earthquake’s epicenter.

Traingulation

A method that uses the S-P time lag from three or more seismograph stations to pinpoint the exact location of an earthquake’s epicenter. Each station creates a circle of possible epicenter locations;the three circles intersect at the epicenter.

Magnitude

A measure of the energy released by an earthquake, typically expressed on the richter scale. Magnitude is a single number for each earthquake.

Intensity

A measure of the damage caused by an earthquake at a specific location, expressed on the mercalli scale. Intensity varies from place to place for the same earthquake.

Shield Volcano

A broad, flat volcano formed from low viscosity(runny) basaltic lava. Lava flows easily and spreads over large areas.

Cinder cone volcano

A small, steep volcano formed from pryoclastic material(ash, cinders, and bombs). These volcanoes form quickly but don’t last long.

Composite(stratovolcano)

A large, steep volcano formed from alternating layers of lava and ash. These are the most dangerous volcanoes because they erupt explosively.

Hot spot

A stationary plume of magma that burns through a moving tectonic plate, creating a chain of volcanic islands.