Ch. 2 - Matter, Energy, and the Physical Environment Flashcards
tsunami
A wave or series of waves produced by the vertical displacement of a large volume of water; also called seismic sea wave. Tsunamis differ from normal, wind-driven waves in their large amplitude, very long wavelength, high velocity of propagation, and potentially large onshore run-up heights.
scientific method
A formalized method for testing ideas with observations that involves several assumptions and a more or less consistent series of interrelated steps.
hypothesis
An educated guess that explains a phenomenon or answers a scientific question.
predictions
A specific statement that can be tested, generally arising from a hypothesis.
experiment
An activity designed to test the validity of a hypothesis by manipulating variables.
variables
In an experiment, a condition that can change.
control
The portion of an experiment in which a variable has been left unmanipulated or untreated.
data
Information that is generally quantitative in nature.
peer review
The process by which a manuscript submitted for publication in an academic journal is examined by other specialists in the field, who provide comments and criticism (generally anonymously), and judge whether the work merits publication in the journal.
theory
A widely accepted, well-tested explanation of one or more cause-and-effect relationships that has been extensively validated by a great amount of research.
matter
Any material that has mass and occupies space.
conservation of matter
(law of) The basic principle that matter may be transformed from one type of substance into others, but it cannot be created or destroyed.
element
A fundamental type of matter; a chemical substance with a given set of properties, which cannot be broken down into constituent substances with other properties. Chemists currently recognize 92 elements that occur in nature, as well as more than 20 others that have been artificially created. These are organized by atomic number and other properties into the Periodic Table of the Elements.
radioactive isotope
An unstable isotope that emits subatomic particles and high-energy radiation as it decays into progressively lighter isotopes until becoming stable.
stable isotope
A nonradioactive form of an element.
atoms
The smallest component of an element that maintains the chemical properties of that element.
isotopes
One of several forms or variants of an element having differing numbers of neutrons in the nucleus of its atoms. Chemically, isotopes of an element behave almost identically, but they have different physical properties because they differ in mass.
radioactive
The quality held by some isotopes in which they spontaneously decay, changing their chemical identity as they shed subatomic particles and emit high-energy radiation.
half-life
The amount of time it takes for one-half the atoms of a radioisotope to emit radiation and decay. Different radioisotopes have different half-lives, ranging from fractions of a second to billions of years.
ions
An electrically charged atom or combination of atoms.
molecules
A combination of two or more atoms.
compound
A molecule composed of atoms of two or more elements.
bond
A chemical–physical connection between two or more atoms; an electrical force linking two atoms together.
solution
A chemical mixture; most often used in reference to liquids, it can also be applied to solid and gaseous mixtures.
pH (scale)
A measure of the concentration of hydrogen ions in a solution. The pH scale ranges from 0 to 14: Solutions with pH of 7 are neutral; solutions with pH below 7 are acidic, and those with pH higher than 7 are basic. Because the pH scale is logarithmic, each step on the scale represents a tenfold difference in hydrogen ion concentration.
organic compounds
A compound made up of carbon atoms (and, generally, hydrogen atoms) joined by covalent bonding and sometimes including other elements, such as nitrogen, oxygen, sulphur, or phosphorus. The unusual ability of carbon to build elaborate molecules has resulted in millions of different organic compounds showing various degrees of complexity.
inorganic compounds
Chemical compounds that are of mineral (rather than biological) origin. Inorganic compounds may contain carbon—the element that characterizes organic compounds—but lack the carbon–carbon bonds that are typical of organic compounds.
hydrocarbons
Organic molecules consisting of only the elements hydrogen and carbon; constituents of fossil fuels.
methane (CH4)
The simplest hydrocarbon compound; the key component of natural gas, and a naturally occurring greenhouse gas.
proteins
A large molecule made up of long chains of amino acids.
nucleic acids
A molecule that directs the production of proteins; includes DNA and RNA.
deoxyribonucleic acid (DNA)
A molecule that directs the production of proteins; self-replicating material that is the main constituent of chromosomes in almost all living organisms.
ribonucleic acid (RNA)
A molecule that is involved in protein synthesis and sometimes in the transmission of genetic information.
genes
A stretch of DNA that represents a unit of hereditary information.
carbohydrates
An organic compound consisting of atoms of carbon, hydrogen, and oxygen.
lipids
One of a chemically diverse group of large, biologically important molecules that are classified together because they do not dissolve in water. Lipids include fats, phospholipids, waxes, pigments, and steroids.
plastics
A synthetic polymer material, mostly derived from the hydrocarbons in petroleum.
energy
An intangible phenomenon that can do work, that is, can change the position, physical state, or temperature of matter. Energy is a property of matter; it can be transferred or converted into a different form, but it cannot be created or destroyed.
potential energy
Energy of position.
kinetic energy
Energy of motion.
electromagnetic spectrum
The range of wavelengths of radiation from shortest (gamma rays) to longest (radio waves).
autotrophs (or primary producers)
An organism that can produce its own food from simple substances in the surrounding environment, most commonly utilizing energy from sunlight. Includes green plants, algae, and cyanobacteria.
photosynthesis
The process by which autotrophs produce their own food. Sunlight powers a series of chemical reactions that convert carbon dioxide and water into sugar (glucose), thus transforming low-quality energy from the sun into high-quality energy the organism can use.
heterotroph (or consumer)
An organism that consumes other organisms. Includes all animals and fungi, as well as microbes (bacteria and protozoa) that decompose organic matter, and even some plants.
cellular respiration
The process by which a cell uses the chemical reactivity of oxygen to split glucose into its constituent parts, water and carbon dioxide, and thereby release chemical energy that can be used to form chemical bonds or to perform other tasks within the cell.
geothermal energy
Energy derived from heat generated deep within Earth. The radioactive decay of elements at depth generates heat that rises to the surface in magma, through heat flow by conduction, and through fissures and cracks. Can be synonymous with terrestrial energy.
chemosynthesis
The process by which bacteria in hydrothermal vents use the chemical energy of hydrogen sulphide (H2S) to transform inorganic carbon into organic compounds.
core
(1) The innermost zone of Earth, made up mostly of iron, that lies beneath the crust and mantle. (2) The part of a forest or reserve that is isolated from the surrounding area by a transitional or buffer zone.
mantle
The layer of rock that lies beneath Earth’s crust and surrounds a mostly iron core.
lithosphere
The solid part of Earth, including the rocks, sediment, and soil at the surface and extending down many kilometres underground; the crust and the outer portion of the mantle.
crust
The relatively low-density outer layer of Earth, consisting of rock that floats atop the malleable mantle, which in turn surrounds a mostly iron core.
convection
A process of heat transfer in which materials that are heated from below rise (as a consequence of lower density), cool, and then sink again (as a consequence of higher density).
plate tectonics
The process by which Earth’s surface is shaped by the extremely slow movement of tectonic plates—large fragments of lithosphere. Earth’s surface includes about 15 major tectonic plates. Their interactions give rise to processes that build mountains, cause earthquakes and volcanic eruptions, and otherwise influence the landscape.
divergent plate boundaries
A boundary along which tectonic plates are moving apart from one another. If magma rising underneath the divergent boundary reaches the surface, new crust is formed as the emerging lava cools and solidifies in the rift. An example is the Mid-Atlantic ridge.
magma
Molten (that is, liquid, melted) rock, typically containing dissolved gases, and sometimes mineral grains and rock fragments.
fault
In rock, a fracture along which some movement has occurred.
transform plate boundaries
A boundary along which two tectonic plates are moving past one another in a translational sense. For example, the Pacific Plate and the North American Plate are slipping and grinding past each other along California’s San Andreas Fault.
convergent plate boundaries
A boundary along which tectonic plates are toward one another. Can result in subduction or collision, and mountain range formation.
subduction
The plate tectonic process by which a tectonic plate carrying dense oceanic crust slides (or is pushed or dragged) beneath another plate at a convergent plate boundary.
continental collision
A convergent boundary between tectonic plates, both of which carry continental crust, leading to the formation of a continental collision zone, rock deformation and metamorphism, and uplift of high mountain chains.
volcano
A vent through which lava, ash, and other volcanic materials are extruded to the surface.
landslides
A type of mass wasting in which a mass of rock or sediment moves downslope, often as a relatively coherent block.
mass wasting
The downslope movement of Earth material (such as rock or soil) under the influence of gravity.
rock cycle
The very slow process in which rocks and the minerals that make them up are heated, melted, cooled, broken, and reassembled, forming igneous, sedimentary, and metamorphic rocks.
rock
Durable Earth material made principally of minerals.
mineral
A naturally occurring, solid, crystalline, inorganic compound; the building blocks of rocks.
lava
Magma that flows or spatters across Earth’s surface.
igneous rock
One of the three main categories of rock. Formed from the cooling and solidification of magma. Granite and basalt are examples of igneous rock.
weathering
The physical, chemical, and biological processes that break down rocks and minerals.
erosion
The removal of material from one place and its transport to another by the action of wind, water, or glacial ice.
sediment
Loose particles, mainly of weathered rock.
sedimentary rock
One of the three main categories of rock. Formed when dissolved minerals seep through sediment layers and act as a kind of glue, crystallizing and binding sediment particles together. Sandstone and shale are examples of sedimentary rock.
metamorphic rock
One of the three main categories of rock. Formed by great heat and/or pressure that reshapes crystals within the rock and changes its appearance, mineral assemblage, physical properties, and sometimes its overall composition. Common metamorphic rocks include marble and slate.
sequestration
Isolation; very long-term storage in a reservoir.
