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203 terms

APES Chapter 2 Vocab

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acidity
Ions are also important for measuring a substance's acidity in a water solution, a chemical characteristic that helps determine how a substance dissolved in water will interact with and affect its environment.
atom
The most basic building block of matter is an atom: the smallest unit of matter into which an element can be divided and still retain its chemical properties.
atomic number
Each element has a unique atomic number, equal to the number of protons in the nucleus of its atom.
atomic theory
The idea that all elements are made up of atoms is called the atomic theory and is the most widely accepted scientific theory in chemistry.
cells
The bridge between nonliving and living matter lies somewhere between macromolecules and cells—the fundamental structural units of life.
chain reaction
Multiple fissions within a certain amount of mass produce a chain reaction, which releases an enormous amount of energy.
chemical change, or chemical reaction
In a chemical change, or chemical reaction, there is a change in the arrangement of atoms or ions within molecules of the substances involved.
chemical formula
Chemists use a chemical formula to show the number of each type of atom or ion in a compound.
chromosome
Thousands of genes, in turn, make up a single chromosome, a special DNA molecule together with a number of proteins.
compounds
combinations of two or more different elements held together in fixed proportions.
data
information needed to answer their questions—scientists make observations of the subject area they are studying.
deductive reasoning
involves using logic to arrive at a specific conclusion based on a generalization or premise.
electromagnetic radiation
another form of kinetic energy, energy travels in the form of a wave as a result of changes in electric and magnetic fields.
electrons (e)
If you could view atoms with a supermicroscope, you would find that each different type of atom contains a certain number of three different types of subatomic particles: positively charged protons (p), neutrons (n) with no electrical charge, and negatively charged electrons (e).
elements
each of which is a fundamental substance that has a unique set of properties and cannot be broken down into simpler substances by chemical means.
energy
the capacity to do work or transfer heat. Work is done when something is moved.
Energy efficiency, or energy productivity
a measure of how much useful work is accomplished by a particular input of energy into a system.
energy quality
a measure of an energy source's capacity to do useful work.
experiments
or procedures carried out under controlled conditions to gather information and test ideas.
feedback
any process that increases (positive feedback) or decreases (negative feedback) a change to a system.
feedback loop
Such a process, called a feedback loop, occurs when an output of matter, energy, or information is fed back into the system as an input and leads to changes in that system.
flows or throughputs
Most systems have the following key components: inputs from the environment, flows or throughputs of matter and energy within the system at certain rates, and outputs to the environment.
genes
Within some DNA molecules are certain sequences of nucleotides called genes.
heat
Another form of kinetic energy is heat: the total kinetic energy of all moving atoms, ions, or molecules within a given substance.
high-quality energy
is concentrated and has a high capacity to do useful work.
high-quality matter
is highly concentrated, is typically found near the earth's surface, and has great potential for use as a resource.
inductive reasoning
involves using specific observations and measurements to arrive at a general conclusion or hypothesis.
inorganic compounds
Table sugar, vitamins, plastics, aspirin, penicillin, and most of the chemicals in your body are organic compounds, which contain at least two carbon atoms combined with atoms of one or more other elements. All other compounds are called inorganic compounds. One exception, methane (CH4), has only one carbon atom but is considered an organic compound.
inputs
Most systems have the following key components: inputs from the environment, flows or throughputs of matter and energy within the system at certain rates, and outputs to the environment.
ion
A second building block of matter is an ion—an atom or groups of atoms with one or more net positive or negative electrical charges.
isotopes
Forms of an element having the same atomic number but different mass numbers are called isotopes of that element.
kinetic energy
Moving matter has kinetic energy because it has mass and velocity.
law of conservation of energy
also known as the first law of thermodynamics: When energy is converted from one form to another in a physical or chemical change, no energy is created or destroyed.
law of conservation of matter
when a physical or chemical change occurs, no atoms are created or destroyed.
low-quality energy
is dispersed and has little capacity to do useful work.
mass number
The mass of an atom is described by its mass number: the total number of neutrons and protons in its nucleus.
matter
anything that has mass and takes up space.
matter quality
a measure of how useful a form of matter is to humans as a resource, based on its availability and concentration, or amount of it that is contained in a given area or volume.
model
an approximate representation or simulation of a system being studied.
molecule
The third building block of matter is a molecule: a combination of two or more atoms of the same or different elements held together by forces called chemical bonds.
natural radioactive decay
In the first type, called natural radioactive decay, isotopes spontaneously emit fast-moving subatomic particles, high-energy radiation such as gamma rays, or both.
negative, or corrective, feedback loop
causes a system to change in the opposite direction from which it is moving.
neutrons (n)
If you could view atoms with a supermicroscope, you would find that each different type of atom contains a certain number of three different types of subatomic particles: positively charged protons (p), neutrons (n) with no electrical charge, and negatively charged electrons (e).
nuclear changes
In addition to physical and chemical changes, matter can undergo three types of nuclear changes, or changes in the nuclei of its atoms.
nuclear fission
a nuclear change in which the nuclei of certain isotopes with large mass numbers (such as uranium-235) are split apart into lighter nuclei when struck by neutrons; each fission releases two or three neutrons plus energy.
nuclear fusion
a nuclear change in which two isotopes of light elements, such as hydrogen, are forced together at extremely high temperatures until they fuse to form a heavier nucleus.
nucleus
Each atom consists of an extremely small and dense center called its nucleus—which contains one or more protons and, in most cases, one or more neutrons.
organic compounds
Table sugar, vitamins, plastics, aspirin, penicillin, and most of the chemicals in your body are organic compounds, which contain at least two carbon atoms combined with atoms of one or more other elements.
outputs
Most systems have the following key components: inputs from the environment, flows or throughputs of matter and energy within the system at certain rates, and outputs to the environment.
paradigm shift
Occasionally, new discoveries and new ideas can overthrow a well-accepted scientific theory or law in what is called a paradigm shift.
peer review
happens when scientists report details of the methods and models they used, the results of their experiments, and the reasoning behind their hypotheses for other scientists working in the same field (their peers) to examine and criticize.
pH
Scientists use pH as a measure of acidity, based on the amount of hydrogen ions (H+) and hydroxide ions (OH-) contained in a particular volume of a solution.
physical change
When a sample of matter undergoes a physical change, its chemical composition, or the arrangement of its atoms or ions within molecules does not change.
positive feedback loop
causes a system to change further in the same direction.
potential energy
The other major type of energy is potential energy, which is stored and potentially available for use.
protons (p)
If you could view atoms with a supermicroscope, you would find that each different type of atom contains a certain number of three different types of subatomic particles: positively charged protons (p), neutrons (n) with no electrical charge, and negatively charged electrons (e).
radioactive decay
occurs when nuclei of unstable isotopes spontaneously emit fast-moving chunks of matter (alpha particles or beta particles), high-energy radiation (gamma rays), or both at a fixed rate. A particular radioactive isotope may emit any one or a combination of the three items shown in the diagram.
radioactive isotopes or radioisotopes
unstable isotopes
reliable science
consists of data, hypotheses, theories, and laws that are widely accepted by scientists who are considered experts in the field under study.
science
an endeavor to discover how nature works and to use that knowledge to make predictions about what is likely to happen in nature.
scientific hypothesis
a possible and testable explanation of what they observe in nature or in the results of their experiments.
scientific law, or law of nature
a well-tested and widely accepted description of what we find happening over and over again in the same way in nature.
scientific theory
A well-tested and widely accepted scientific hypothesis or a group of related hypotheses
second law of thermodynamics
When energy changes from one form to another, we always end up with lower-quality or less usable energy than we started with. This lower-quality energy usually takes the form of heat given off at a low temperature to the environment.
synergistic interaction, or synergy
occurs when two or more processes interact so that the combined effect is greater than the sum of their separate effects.
system
a set of components that function and interact in some regular way.
tentative science or frontier science
Sometimes, preliminary results that capture news headlines are controversial because they have not been widely tested and accepted by peer review. They are not yet considered reliable, and can be thought of as tentative science or frontier science.
time delays
Complex systems often show time delays between the input of a feedback stimulus and the response to it.
tipping point
Time delays can also allow an environmental problem to build slowly until it reaches a threshold level, or tipping point, causing a fundamental shift in the behavior of a system.
trait
Each of these coded units of genetic information concerns a specific trait, or characteristic passed on from parents to offspring during reproduction in an animal or plant.
unreliable science
Scientific hypotheses and results that are presented as reliable without having undergone the rigors of peer review, or that have been discarded as a result of peer review, are considered to be unreliable science.
acid
See acidic solution.
acid solution
Any water solution that has more hydrogen ions (H+) than hydroxide ions (OH[[minus]]); any water solution with a pH less than 7. Compare basic solution, neutral solution.
acidic solution
Any water solution that has more hydrogen ions (H+) than hydroxide ions (OH-); any water solution with a pH less than 7. Compare basic solution, neutral solution.
alpha particle
Positively charged matter, consisting of two neutrons and two protons, that is emitted as a form of radioactivity from the nuclei of some radioisotopes. See also beta particle, gamma rays.
atom
Minute unit made of subatomic particles that is the basic building block of all chemical elements and thus all matter; the smallest unit of an element that can exist and still have the unique characteristics of that element. Compare ion, molecule.
atomic number
Number of protons in the nucleus of an atom. Compare mass number.
basic solution
Water solution with more hydroxide ions (OH[[minus]]) than hydrogen ions (H+); water solution with a pH greater than 7. Compare acid solution, neutral solution.
beta particle
Swiftly moving electron emitted by the nucleus of a radioactive isotope. See also alpha particle, gamma rays.
biodegradable
Capable of being broken down by decomposers.
biodegradable pollutant
Material that can be broken down into simpler substances (elements and compounds) by bacteria or other decomposers. Paper and most organic wastes such as animal manure are biodegradable but can take decades to biodegrade in modern landfills. Compare degradable pollutant, nondegradable pollutant, slowly degradable pollutant.
chain reaction
Multiple nuclear fissions, taking place within a certain mass of a fissionable isotope, that release an enormous amount of energy in a short time.
chemical
One of the millions of different elements and compounds found naturally and synthesized by humans. See compound, element.
chemical change
Interaction between chemicals in which there is a change in the chemical composition of the elements or compounds involved. Compare nuclear change, physical change.
chemical formula
Shorthand way to show the number of atoms (or ions) in the basic structural unit of a compound. Examples are H2O, NaCl, and C6H12O6.
chemical reaction
See chemical change.
chlorinated hydrocarbon
Organic compound made up of atoms of carbon, hydrogen, and chlorine. Examples are DDT and PCBs.
chromosome
A grouping of various genes and associated proteins in plant and animal cells that carry certain types of genetic information. See genes.
complex carbohydrates
Two or more monomers of simple sugars (such as glucose) linked together.
compound
Combination of atoms, or oppositely charged ions, of two or more different elements held together by attractive forces called chemical bonds. Compare element.
concentration
Amount of a chemical in a particular volume or weight of air, water, soil, or other medium.
consensus science
See sound science.
corrective feedback loop
See negative feedback loop.
critical mass
Amount of fissionable nuclei needed to sustain a nuclear fission chain reaction.
deductive reasoning
Using logic to arrive at a specific conclusion based on a generalization or premise. It goes from the general to the specific. Compare inductive reasoning.
degradable pollutant
Potentially polluting chemical that is broken down completely or reduced to acceptable levels by natural physical, chemical, and biological processes. Compare biodegradable pollutant, nondegradable pollutant, slowly degradable pollutant.
deuterium (D; hydrogen-2)
Isotope of the element hydrogen, with a nucleus containing one proton and one neutron and a mass number of 2.
DNA (deoxyribonucleic acid)
Large molecules in the cells of organisms that carry genetic information in living organisms.
electromagnetic radiation
Forms of kinetic energy traveling as electromagnetic waves. Examples are radio waves, TV waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X rays, and gamma rays. Compare ionizing radiation, nonionizing radiation.
electron (e)
Tiny particle moving around outside the nucleus of an atom. Each electron has one unit of negative charge and almost no mass. Compare neutron, proton.
element
Chemical, such as hydrogen (H), iron (Fe), sodium (Na), carbon (C), nitrogen (N), or oxygen (O), whose distinctly different atoms serve as the basic building blocks of all matter. Two or more elements combine to form compounds that make up most of the world's matter. Compare compound.
energy
Capacity to do work by performing mechanical, physical, chemical, or electrical tasks or to cause a heat transfer between two objects at different temperatures.
energy efficiency
Percentage of the total energy input that does useful work and is not converted into low-quality, usually useless heat in an energy conversion system or process. See energy quality, net energy. Compare material efficiency.
energy productivity
See energy efficiency.
energy quality
Ability of a form of energy to do useful work. High-temperature heat and the chemical energy in fossil fuels and nuclear fuels are concentrated high-quality energy. Low-quality energy such as low-temperature heat is dispersed or diluted and cannot do much useful work. See high-quality energy, low-quality energy.
eukaryotic cell
Cell containing a nucleus, a region of genetic material surrounded by a membrane. Membranes also enclose several of the other internal parts found in a eukaryotic cell. Compare prokaryotic cell.
eukaryotic organism
Classification of cell structure in which the cell is surrounded by a membrane and has a distinct nucleus and several other internal parts. Most organisms consist of eukaryotic cells. Compare prokaryotic organism.
experiment
Procedure a scientist uses to study some phenomenon under known conditions. Scientists conduct some experiments in the laboratory and others in nature. The resulting scientific data or facts must be verified or confirmed by repeated observations and measurements, ideally by several different investigators.
feedback loop
Circuit of sensing, evaluating, and reacting to changes in environmental conditions as a result of information fed back into a system; it occurs when one change leads to some other change, which eventually reinforces or slows the original change. See negative feedback loop, positive feedback loop.
first law of thermodynamics
In any physical or chemical change, no detectable amount of energy is created or destroyed, but in these processes energy can be changed from one form to another; you cannot get more energy out of something than you put in; in terms of energy quantity, you cannot get something for nothing (there is no free lunch). This law does not apply to nuclear changes, in which energy can be produced from small amounts of matter. See second law of thermodynamics.
flows
See throughputs.
frontier science
Preliminary scientific data, hypotheses, and models that have not been widely tested and accepted. Compare junk science, sound science.
gamma rays
A form of ionizing electromagnetic radiation with a high energy content emitted by some radioisotopes. They readily penetrate body tissues. See also alpha particle, beta particle.
genes
Coded units of information about specific traits that are passed on from parents to offspring during reproduction. They consist of segments of DNA molecules found in chromosomes.
half-life
Time needed for one-half of the nuclei in a radioisotope to emit its radiation. Each radioisotope has a characteristic half-life, which may range from a few millionths of a second to several billion years. See radioisotope.
heat
Total kinetic energy of all the randomly moving atoms, ions, or molecules within a given substance, excluding the overall motion of the whole object. Heat always flows spontaneously from a hot sample of matter to a colder sample of matter. This is one way to state the second law of thermodynamics. Compare temperature.
high-quality energy
Energy that is concentrated and has great ability to perform useful work. Examples are high-temperature heat and the energy in electricity, coal, oil, gasoline, sunlight, and nuclei of uranium-235. Compare low-quality energy.
high-quality matter
Matter that is concentrated and contains a high concentration of a useful resource. Compare low-quality matter.
high-throughput economy
The situation in most advanced industrialized countries, in which ever-increasing economic growth is sustained by maximizing the rate at which matter and energy resources are used, with little emphasis on pollution prevention, recycling, reuse, reduction of unnecessary waste, and other forms of resource conservation. Compare low-throughput economy, matter-recycling economy.
high-waste economy
See high-throughput economy.
hydrocarbon
Organic compound of hydrogen and carbon atoms. The simplest hydrocarbon is methane (CH4), the major component of natural gas.
inductive reasoning
Using observations and facts to arrive at generalizations or hypotheses. It goes from the specific to the general and is widely used in science. Compare deductive reasoning.
inorganic compounds
All compounds not classified as organic compounds. See organic compounds.
input
Matter, energy, or information entering a system. Compare output, throughput.
ion
Atom or group of atoms with one or more positive (+) or negative ([[minus]]) electrical charges. Compare atom, molecule.
ionizing radiation
Fast-moving alpha or beta particles or high-energy radiation (gamma rays) emitted by radioisotopes. They have enough energy to dislodge one or more electrons from atoms they hit, forming charged ions in tissue that can react with and damage living tissue. Compare nonionizing radiation.
isotopes
Two or more forms of a chemical element that have the same number of protons but different mass numbers because they have different numbers of neutrons in their nuclei.
junk science
Scientific results or hypotheses presented as sound science but not having undergone the rigors of the peer review process. Compare frontier science, sound science.
kinetic energy
Energy that matter has because of its mass and speed or velocity. Compare potential energy.
law of conservation of energy
See first law of thermodynamics.
law of conservation of matter
In any physical or chemical change, matter is neither created nor destroyed but merely changed from one form to another; in physical and chemical changes, existing atoms are rearranged into different spatial patterns (physical changes) or different combinations (chemical changes).
lipids
Chemically diverse group of large organic compounds that do not dissolve in water. Examples are fats and oils for storing energy, waxes for structure, and steroids for producing hormones.
low-quality energy
Energy that is dispersed and has little ability to do useful work. An example is low-temperature heat. Compare high-quality energy.
low-quality matter
Matter that is dilute or dispersed or contains a low concentration of a useful resource. Compare high-quality matter.
low-throughput economy
Economy based on working with nature by recycling and reusing discarded matter, preventing pollution, conserving matter and energy resources by reducing unnecessary waste and use, not degrading renewable resources, building things that are easy to recycle, reuse, and repair, not allowing population size to exceed the carrying capacity of the environment, and preserving biodiversity and ecological integrity. See environmental worldview. Compare high-throughput economy, matter-recycling economy.
low-waste economy
See low-throughput economy.
mass
The amount of material in an object.
mass number
Sum of the number of neutrons (n) and the number of protons (p) in the nucleus of an atom. It gives the approximate mass of that atom. Compare atomic number.
material efficiency
Total amount of material needed to produce each unit of goods or services. Also called resource productivity. Compare energy efficiency.
matter
Anything that has mass (the amount of material in an object) and takes up space. On the earth, where gravity is present, we weigh an object to determine its mass.
matter quality
Measure of how useful a matter resource is, based on its availability and concentration. See high-quality matter, low-quality matter.
matter-recycling economy
Economy that emphasizes recycling the maximum amount of all resources that can be recycled. The goal is to allow economic growth to continue without depleting matter resources and without producing excessive pollution and environmental degradation. Compare high-throughput economy, low-throughput economy.
mixture
Combination of one or more elements and compounds.
model
An approximate representation or simulation of a system being studied.
molecule
Combination of two or more atoms of the same chemical element (such as O2) or different chemical elements (such as H2O) held together by chemical bonds. Compare atom, ion.
natural law
See scientific law.
natural radioactive decay
Nuclear change in which unstable nuclei of atoms spontaneously shoot out particles (usually alpha or beta particles) or energy (gamma rays) at a fixed rate.
negative feedback loop
Situation in which a change in a certain direction provides information that causes a system to change less in that direction. Compare positive feedback loop.
neutral solution
Water solution containing an equal number of hydrogen ions (H+) and hydroxide ions (OH[[minus]]); water solution with a pH of 7. Compare acid solution, basic solution.
neutron (n)
Elementary particle in the nuclei of all atoms (except hydrogen-1). It has a relative mass of 1 and no electric charge. Compare electron, proton.
nondegradable pollutant
Material that is not broken down by natural processes. Examples are the toxic elements lead and mercury. Compare biodegradable pollutant, degradable pollutant, slowly degradable pollutant.
nonionizing radiation
Forms of radiant energy such as radio waves, microwaves, infrared light, and ordinary light that do not have enough energy to cause ionization of atoms in living tissue. Compare ionizing radiation.
nonpersistent pollutant
See degradable pollutant.
nuclear change
Process in which nuclei of certain isotopes spontaneously change, or are forced to change, into one or more different isotopes. The three principal types of nuclear change are natural radioactivity, nuclear fission, and nuclear fusion. Compare chemical change, physical change.
nuclear energy
Energy released when atomic nuclei undergo a nuclear reaction such as the spontaneous emission of radioactivity, nuclear fission, or nuclear fusion.
nuclear fission
Nuclear change in which the nuclei of certain isotopes with large mass numbers (such as uranium-235 and plutonium-239) are split apart into lighter nuclei when struck by a neutron. This process releases more neutrons and a large amount of energy. Compare nuclear fusion.
nucleic acids
Large polymer molecules made by linking hundreds to thousands of four types of monomers called nucleotides.
nucleus
Extremely tiny center of an atom, making up most of the atom's mass. It contains one or more positively charged protons and one or more neutrons with no electrical charge (except for a hydrogen-1 atom, which has one proton and no neutrons in its nucleus).
organic compounds
Compounds containing carbon atoms combined with each other and with atoms of one or more other elements such as hydrogen, oxygen, nitrogen, sulfur, phosphorus, chlorine, and fluorine. All other compounds are called inorganic compounds.
output
Matter, energy, or information leaving a system. Compare input, throughput.
paradigm shifts
Shifts in scientific thinking that occur when the majority of scientists in a field or related fields agree that a new explanation or theory is better than the old one.
parts per billion (ppb)
Number of parts of a chemical found in 1 billion parts of a particular gas, liquid, or solid.
parts per million (ppm)
Number of parts of a chemical found in 1 million parts of a particular gas, liquid, or solid.
parts per trillion (ppt)
Number of parts of a chemical found in 1 trillion parts of a particular gas, liquid, or solid.
persistence
How long a pollutant stays in the air, water, soil, or body. See also inertia.
persistent pollutant
See slowly degradable pollutant.
pH
Numeric value that indicates the relative acidity or alkalinity of a substance on a scale of 0 to 14, with the neutral point at 7. Acid solutions have pH values lower than 7, and basic or alkaline solutions have pH values greater than 7.
physical change
Process that alters one or more physical properties of an element or a compound without altering its chemical composition. Examples are changing the size and shape of a sample of matter (crushing ice and cutting aluminum foil) and changing a sample of matter from one physical state to another (boiling and freezing water). Compare chemical change, nuclear change.
positive feedback loop
Situation in which a change in a certain direction provides information that causes a system to change further in the same direction. Compare negative feedback loop.
potential energy
Energy stored in an object because of its position or the position of its parts. Compare kinetic energy.
ppb
See parts per billion.
ppm
See parts per million.
ppt
See parts per trillion.
prokaryotic cell
Cell that does not have a distinct nucleus. Other internal parts are also not enclosed by membranes. Compare eukaryotic cell.
prokaryotic organism
Classification of cell structure in which the cell contains no distinct nucleus or organelles enclosed by membranes. A prokaryotic cell is much simpler and usually much smaller than a eukaryotic cell. All bacteria are single-celled prokaryotic organisms. Compare eukaryotic organism.
proteins
Large polymer molecules formed by linking together long chains of monomers called amino acids.
proton (p)
Positively charged particle in the nuclei of all atoms. Each proton has a relative mass of 1 and a single positive charge. Compare electron, neutron.
radiation
Fast-moving particles (particulate radiation) or waves of energy (electromagnetic radiation). See alpha particle, beta particle, gamma rays.
radioactive decay
Change of a radioisotope to a different isotope by the emission of radioactivity.
radioactive isotope
See radioisotope.
radioactivity
Nuclear change in which unstable nuclei of atoms spontaneously shoot out "chunks" of mass, energy, or both at a fixed rate. The three principal types of radioactivity are gamma rays and fast-moving alpha particles and beta particles.
radioisotope
Isotope of an atom that spontaneously emits one or more types of radioactivity (alpha particles, beta particles, gamma rays).
resource productivity
See material efficiency.
science
Attempts to discover order in nature and use that knowledge to make predictions about what should happen in nature. See frontier science, scientific data, scientific hypothesis, scientific law, scientific methods, scientific model, scientific theory, sound science.
scientific data
Facts obtained by making observations and measurements. Compare scientific hypothesis, scientific law, scientific methods, scientific model, scientific theory.
scientific hypothesis
An educated guess that attempts to explain a scientific law or certain scientific observations. Compare scientific data, scientific law, scientific methods, scientific model, scientific theory.
scientific law
Description of what scientists find happening in nature repeatedly in the same way, without known exception. See first law of thermodynamics, law of conservation of matter, second law of thermodynamics. Compare scientific data, scientific hypothesis, scientific methods, scientific model, scientific theory.
scientific methods
The ways scientists gather data and formulate and test scientific hypotheses, models, theories, and laws. See scientific data, scientific hypothesis, scientific law, scientific model, scientific theory.
scientific model
A simulation of complex processes and systems. Many are mathematical models that are run and tested using computers.
scientific theory
A well-tested and widely accepted scientific hypothesis. Compare scientific data, scientific hypothesis, scientific law, scientific methods, scientific model.
second law of energy
See second law of thermodynamics.
second law of thermodynamics
In any conversion of heat energy to useful work, some of the initial energy input is always degraded to a lower-quality, more dispersed, less useful energy, usually low-temperature heat that flows into the environment; you cannot break even in terms of energy quality. See first law of thermodynamics.
slowly degradable pollutant
Material that is slowly broken down into simpler chemicals or reduced to acceptable levels by natural physical, chemical, and biological processes. Compare biodegradable pollutant, degradable pollutant, nondegradable pollutant.
solar energy
Direct radiant energy from the sun and a number of indirect forms of energy produced by the direct input. Principal indirect forms of solar energy include wind, falling and flowing water (hydropower), and biomass (solar energy converted into chemical energy stored in the chemical bonds of organic compounds in trees and other plants).
sound science
Scientific data, models, theories, and laws that are widely accepted by scientists considered experts in the area of study. These results of science are very reliable. Compare frontier science, junk science.
subatomic particles
Extremely small particles-electrons, protons, and neutrons-that make up the internal structure of atoms.
synergistic interaction
Interaction of two or more factors or processes so that the combined effect is greater than the sum of their separate effects.
synergy
See synergistic interaction.
system
A set of components that function and interact in some regular and theoretically predictable manner.
temperature
Measure of the average speed of motion of the atoms, ions, or molecules in a substance or combination of substances at a given moment. Compare heat.
throughput
Rate of flow of matter, energy, or information through a system. Compare input, output.
throwaway society
See high-throughput economy.
time delay
Time lag between the input of a stimulus into a system and the response to the stimulus.