CS_SE_BackMatter 3/17/05 7:29 PM Page 1005 Glossary Glossary abiotic: the nonliving components of an ecosystem angle of incidence: the angle a ray of light makes absolute zero: the temperature at which all with the normal to the surface at the point of vibrations of the atoms and molecules of matter incidence cease; the lowest possible temperature angle of reflection: the angle a reflected ray makes absorption spectrum: a continuous spectrum with the normal to the surface at the point of interrupted by absorption lines or a continuous reflection spectrum having a number of discrete wavelengths anion: a negatively charged ion missing or reduced in intensity anthropogenic: generated or produced by human acceleration: the change in velocity per unit time activities ∆ a ϭ ᎏᎏv antinode: a point on a standing wave where the ∆t displacement of the medium is at its maximum accretion: the process whereby dust and gas aphelion: the point in the Earth’s orbit that is accumulated into larger bodies like stars and planets farthest from the Sun. Currently, the Earth reaches aphelion in early July. accuracy: how close the measured value is to the standard or accepted value of that measurement aquifer: any body of sediment or rock that has sufficient size and sufficiently high porosity and acid: a compound or solution with a concentration permeability to provide an adequate supply of water of hydrogen ions greater than the neutral value from wells (corresponding to a pH value of less than 7) ash: fine pyroclastic material (less than 2 mm in acid: a substance that produces hydrogen ions in diameter) water, or is a proton donor asteroid: a small planetary body in acid-base indicator: a dye that has a certain color in orbit around the Sun, larger than a an acid solution and a different color in a base meteoroid (a particle in space, less solution than a few meters in diameter) but adaptation: an inherited trait or set of traits that smaller than a planet. Many asteroids improve the chance of survival and reproduction of can be found in a belt between the orbits an organism of Mars and Jupiter. adaptive radiation: the diversification by natural asthenosphere: the part of the mantle selection, over evolutionary time, of a species or beneath the lithosphere. The group of species into several different species that asthenosphere undergoes slow flow, rather are typically adapted to different ecological niches than behaving as a rigid block, like the air resistance: a force by the air on a moving object; overlying lithosphere. the force is dependent on the speed, volume, and astronomical unit: a unit of measurement equal to mass of the object as well as on the properties of the the average distance between the Sun and Earth, i.e., air, like density about 149,600,000 (1.496 ϫ 108) km albedo: the reflective property of a non-luminous atom: the smallest particle of an element that has all object. A perfect mirror would have an albedo of the element’s properties; it consists of a nucleus 100% while a black hole would have an albedo of surrounded by electrons 0%. atom: the smallest representative part of an element alloy: A substance that has metal characteristics and atomic mass unit (amu): a unit of mass defined as consists of two or more different elements one-twelfth of the mass of a carbon-12 atom alternating current: an electric current that reverses atomic mass unit: a standard unit of atomic mass in direction based on the mass of the carbon atom, which is ampere: the SI unit for electric current; one ampere assigned the value of 12 (1 A) is the flow of one coulomb of charge every atomic mass: atomic mass is determined by the second mass of the protons and neutrons of the atom amplitude: the maximum displacement of a particle aurora: the bright emission of atoms and molecules as a wave passes; the height of a wave crest; it is near the Earth’s poles caused by charged particles related to a wave’s energy entering the upper atmosphere anatomy: the (study of) internal structure of organisms 1005 Coordinated Science for the 21st Century CS_SE_BackMatter 3/17/05 7:29 PM Page 1006 Glossary Coordinated Science for the 21st Century autotroph: an organism that is capable of obtaining body fossil: any remains or imprint of actual organic its energy (food) directly from the physical material from a creature or plant that has been environment preserved in the geologic record (like a bone) Avogadro’s number: The number of atoms bounce: the ability of an object to rebound to its contained in 12 grams of carbon-12. The number is original position when dropped from a given height 23 6.022 x 10 . caldera: a large basin-shaped volcanic depression, axial precession: the wobble in the Earth’s polar more or less circular, the diameter of which is many axis times greater than that of the included vent or vents background extinction: normal extinction of species carbon cycle: the global cycle of movement of that occurs as a result of changes in local carbon, in all of its forms, from one reservoir to environmental conditions another basalt: a kind of volcanic igneous rock, usually dark carbon cycle: the process in which carbon is passed colored, with a high content of iron from one organism to another, then to the abiotic base: a compound or solution with a concentration community, and finally back to the plants of hydrogen ions less than the neutral value carnivore: an animal that feeds exclusively on other (corresponding to a pH value of greater than 7) animals base: a substance that releases hydroxide ions (OH–) carrying capacity: the maximum population that in water, or is a proton acceptor can be sustained by a given supply of resources bias: a purposeful or accidental distortion of catalyst: a substance that changes the speed of a observations, data, or calculations in a systematic or chemical reaction without being permanently nonrandom manner changed itself bilateral symmetry: a body plan that divides the cation: a positively charged ion body into symmetrical left and right halves cement: new mineral material precipitated around binary compound: a compound formed from the the particles of sediment when it is buried below the combining of two different elements Earth’s surface biodiversity: the diversity of different biologic center of mass: the point at which all the mass of species and/or the genetic variability among an object is considered to be concentrated for individuals within each species calculations concerning motion of the object biodiversity: the sum of all the different types of centripetal acceleration: the inward radial organisms living on Earth acceleration of an object moving at a constant speed biodiversity curve: a graph that shows changes in in a circle the diversity of organisms as a function of geologic v2 a ϭ ᎏ time R biomass: the total mass of living matter in the form centripetal force: a force directed towards the of one or more kinds of organisms present in a center that causes an object to follow a circular path particular habitat mv2 F ϭ ᎏᎏᎏ biome: a recognizable assemblage of plants and R animals that characterizes a large geographic area of the Earth; a number of different biomes have been chemical change: a change that converts the recognized, and the distribution of the biomes is chemical composition of a substance into different controlled mainly by climate substance(s) with different chemical composition biosphere: the area on Earth where living organisms chemical energy: energy stored in a chemical can be found compound, which can be released during chemical biotic: the living components of an ecosystem reactions, including combustion birthrate (natality): the rate at which reproduction increases the size of a population 1006 CS_SE_BackMatter 3/17/05 7:29 PM Page 1007 Glossary chemical formula: the combination of the symbols community: all the populations of organisms of the elements in a definite numerical proportion occupying a given area used to represent molecules, compounds, radicals, composite: a solid heterogeneous mixture of two or ions, etc. more substances that make use of the properties of chemical group: a family of elements in the periodic each component table that have similar electron configurations composite cone (stratovolcano): a volcano that is chemical property: a characteristic that a substance constructed of alternating layers of lava and undergoes in a chemical reaction that produces new pyroclastic deposits substance(s) compound: a material that consists of two or more chemical reaction: a process in which new elements united together in definite proportion substance(s) are formed from starting substance(s) concave lens: a lens that causes parallel light rays to chemical test: a physical procedure or chemical diverge; a lens that is thicker at its edges than in the reaction used to identify a substance center chromosome: threads of genetic material found in concentration: a measure of the composition of a the nucleus of cells solution, often given in terms of moles of solute per chromosphere: a reddish layer in the Sun’s liter of solution atmosphere, the transition between the outermost condensation: the process of changing from a gas to layer of the Sun’s atmosphere, or corona a liquid climate: the general pattern of weather conditions conduction: (of heat) the energy transfer from one for a region over a long period of time (at least 30 material or particle to another when the materials or years) particles are in direct contact climate proxy: any feature or set of data that has a conduction: a