Earth's Physical Systems: Matter, Energy, and Geology

Vocabulary practice flashcards covering fundamental chemistry, forms and laws of energy, cellular metabolism, plate tectonics, the rock cycle, and geologic hazards from Chapter 2.

Matter

Any material that has mass and occupies space.

Chemistry

The scientific study of the interactions and properties of matter.

Law of Conservation of Matter

The physical principle stating that matter can be transformed from one type of substance to another, but cannot be created or destroyed.

Element

A fundamental chemical substance with specific properties that cannot be broken down into substances with other properties.

Atom

The smallest unit of matter that still possesses all the chemical properties of an element.

Protons

Positively charged subatomic particles situated in the nucleus of an atom that determine the element's atomic number.

Neutrons

Subatomic particles located within the nucleus of an atom that carry no electrical charge.

Electrons

Negatively charged subatomic particles that orbit the nucleus of an atom.

Mass Number

The total number of protons and neutrons contained within an atom's nucleus.

Isotope

Atoms of the same element that share the same number of protons but differ in their number of neutrons, resulting in different atomic masses.

Radioisotope

An unstable isotope that decays and changes its identity by emitting subatomic particles and high-energy radiation.

Half-Life

The time required for half of the atoms in a given sample of a radioisotope to undergo radioactive decay.

Ion

An electrically charged atom or combination of atoms formed when an atom gains or loses electrons.

Ionizing Radiation

High-energy radiation emitted by radioisotopes that has sufficient energy to knock electrons off molecules and generate ions, altering molecular stability.

Molecule

A chemical particle composed of two or more atoms joined together by chemical bonds, such as $O_2$.

Compound

A molecule composed of atoms of two or more different elements chemically bonded together, such as $H_2O$ or $CO_2$.

Covalent Bond

A chemical bond formed when adjacent atoms share pairs of electrons.

Hydrogen Bond

A weak electrostatic interaction that forms between the oppositely charged poles of adjacent polar molecules, such as between water molecules.

Ionic Bond

A chemical bond formed by the electrostatic attraction between oppositely charged ions created when electrons transfer completely from one atom to another.

Hydrocarbon

An organic compound consisting exclusively of bonded carbon and hydrogen atoms, forming the basis of petroleum and fossil fuels.

Polymer

A large molecule composed of repeating chains of smaller, identical or similar sub-units.

Proteins

Macromolecules consisting of amino acid polymers that provide structural support, compose skin and muscle, assist the immune system, and serve as enzymes.

Nucleic Acids

Biological polymers composed of nucleotides (including DNA and RNA) that carry hereditary information and direct protein production in cells.

Gene

A distinct segment of DNA along a chromosome that encodes the blueprint for manufacturing a specific protein.

Carbohydrates

A category of macromolecules including simple and complex sugars (such as glucose, cellulose, and chitin) used by organisms for energy storage and structural support.

Lipids

A chemically diverse group of water-insoluble molecules that include fats and oils for energy storage, waxes for structure, and steroids in hormones.

pH Scale

A logarithmic measurement scale ranging from 0 to 14 quantifying the concentration of hydrogen ions ($H^+$) in solution, where 7 is neutral, values below 7 are acidic, and values above 7 are basic.

Potential Energy

The stored energy of position or chemical composition.

Kinetic Energy

The active energy of motion.

First Law of Thermodynamics

The physical law stating that energy can change from one form to another, but cannot be created or destroyed.

Second Law of Thermodynamics

The physical law stating that energy changes from a more-ordered state to a less-ordered state (increasing in entropy) whenever it undergoes a transformation.

Autotroph

An organism that directly harnesses solar radiation or chemical energy to produce its own food.

Photosynthesis

The biological process in chloroplasts that uses sunlight to convert low-energy water and carbon dioxide molecules into high-energy sugars and oxygen gas.

Cellular Respiration

The metabolic process occurring in autotrophs and heterotrophs that releases chemical energy by reacting glucose ($C_6H_{12}O_6$) with oxygen ($O_2$) to produce carbon dioxide ($CO_2$) and water ($H_2O$).

Heterotroph

An organism that cannot synthesize its own food and must satisfy its nutritional and energy requirements by consuming other organisms.

Chemosynthesis

The autotrophic process used by bacteria at hydrothermal vents that produces sugar from the chemical energy in hydrogen sulfide ($H_2S$): $6CO_2 + 6H_2O + 3H_2S \rightarrow C_6H_{12}O_6 + 3H_2SO_4$.

Geology

The scientific study of Earth's physical features, processes, and historical development.

Core

The dense center of Earth, composed of solid iron surrounded by an outer layer of molten iron.

Mantle

A thick geological layer of less-dense, elastic rock surrounding Earth's metallic core.

Asthenosphere

A ductile, softer region of Earth's upper mantle situated directly beneath the lithosphere.

Lithosphere

The hard outer layer of Earth comprising the brittle crust and the uppermost portion of the mantle.

Crust

The thin, brittle, low-density outer rock layer covering Earth's surface.

Plate Tectonics

The geological process driven by mantle convection currents where large slabs of the lithosphere move approximately $2\text{ to }15\text{ cm}$ per year.

Divergent Plate Boundary

A tectonic boundary where plates pull apart as rising magma erupts, cools, and generates new oceanic crust.

Transform Plate Boundary

A tectonic boundary where plates slide and grind horizontally past one another along a fault line, triggering earthquakes.

Subduction

The convergent boundary process where denser oceanic crust dives downward into the mantle beneath lighter continental or oceanic crust.

Continental Collision

A convergent boundary process in which two continental plates collide, compress, bend, and buckle upwards to construct mountain ranges.

Mineral

A naturally occurring, solid inorganic chemical element or compound characterized by a definite crystalline structure and specific physical properties.

Rock

Any naturally formed solid aggregation of one or more minerals.

Rock Cycle

The continuous geological process over time wherein rocks and minerals are heated, melted, cooled, weathered, deposited, and transformed.

Igneous Rock

Rock formed directly from the cooling and solidification of molten magma or lava.

Intrusive Igneous Rock

Coarse-grained igneous rock (such as granite) formed when magma cools slowly beneath Earth's surface, allowing coarse crystals to grow.

Extrusive Igneous Rock

Fine-grained, smooth igneous rock (such as basalt) formed when magma erupts onto Earth's surface as lava and cools rapidly.

Sedimentary Rock

Rock formed when weathered particles of sediment accumulate in layers, are compacted under pressure, and become cemented by dissolved minerals.

Metamorphic Rock

Rock formed when existing rock is chemically or physically transformed by extreme heat and pressure without undergoing complete melting.

Anthropocene

A proposed modern geological epoch characterized by profound human impacts on Earth's systems, marked by sharp global increases in erosion rates, atmospheric $CO_2$, and human population.

Earthquake

A sudden release of accumulated energy at a tectonic plate boundary or internal fault line.

Hotspot

A localized volcanic site produced by a stationary plume of molten magma rising from the mantle through the crust, often forming a linear island chain as plates drift overhead.

Mass Wasting

The downhill gravitational movement and collapse of large masses of rock and soil along unstable slopes.

Tsunami

A massive surge of seawater displaced and propelled across the ocean by an earthquake, underwater volcanic eruption, or major coastal landslide.