APES Chapter 2 Vocabulary

An attempt to discover order in the natural world and to use that knowledge to make predictions about what is likely to happen in nature

Tests performed to study phenomenon under known conditions

Possible answer to a question posed by scientists

Well tested and widely accepted scientific hypothesis. The best and most useful answer to a science question based on available knowledge, research, and evaluation by scientists in the involved fields

Description of what we find happening in nature over and over in the same way

Using specific observations and measurements to arrive at a general conclusion or hypothesis

Using logic to arrive at a specific conclusion based on a generalization or premise

New information or ideas disprove and overthrow a well-accepted scientific theory

Preliminary results not widely tested and accepted by peer review

Data, theories, and laws widely accepted by scientists considered experts in the field

Scientific results or hypotheses presented as sound science without undergoing (or discredited by) peer review

Set of components that function and interact in some regular and theoretically understandable manner

Matter, energy, or information entering a system

Matter, energy, or information leaving a system

Rate of flow of matter, energy, or information through a system

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

Causes a system to change further in the same direction

Causes a system to change int he opposite direction

Amount of time in a feedback loop between the input of a stimulus and the response to it

Two or more processes interact so that the combined effect is greater than the sum of their separate effects

Anything that has mass and takes up space

Distinctive building blocks of matter that make up every material substance

Two or more different elements held together in fixed apportions by chemical bonds

The smallest unit of matter that exhibits the characteristics of an element

Positively charged atoms

Uncharged atoms

Negatively charged atoms

Extremely small center of atom containing one or more protons (and usually neutrons)

The number of protons in the nucleus of each of atom of an element

Total number of neutrons and protons in the nucleus of an atom of an element

Same atomic number, different mass numbers

Atom or groups of atoms with one or more net positive (+) or negative (-) electrical charges

Measure of the acidity of a solution based on its concentration of hydrogen ions

pH = 7

pH less than 7 (more hydrogen ions than hydroxide ions)

pH greater than 7 (more hydroxide ions than hydrogen ions)

Combination of two or more atoms of the same or different elements held together by chemical bonds

Shows the number of atoms or ions of each type in a compound

Contain at least two carbon atoms combined with each other and with atoms of one or more other elements

All compounds that are not organic compounds

Minute compartments containing chemicals necessary for life and within which most of the processes of life take place

Cell structure in which cell is surrounded by a membrane and has a distinct nucleus and several other organelles

Cell structure in which membrane surrounds the cell, but the cell contains no distinct nucleus or organelles enclosed by membranes

Larger and more complex organic compounds that make up the basic molecular units found in living organisms

Specific sequences of nucleotides found within a DNA molecule that contain information to make specific proteins

Combinations of genes that make up a single DNA molecule, together with a number of proteins

Measure of how useful a form of matter is to humans as a resource, based on its availability and concentration

Concentrated, typically found near the earth's surface, has great potential for use as a matter resource

Dilute, often located deep underground or dispersed in the ocean or the atmosphere, usually has little potential for use as a material resource

Is the total amount or material needed to produce each unit of goods or services

Chemical composition does not change

There is a change in the chemical compositions of the elements or compounds involved

When a physical or chemical change occurs, no atoms are created or destroyed

Measure of how long the pollutant stays in the air, water, soil, or body

Broken down completely or reduced to acceptable levels by natural physical, chemical, and biological processes

Complex chemical pollutants that living organism (usually specialized bacteria) break down into simpler chemicals

Take decades or longer to degrade

Chemicals that natural processes cannot break down

Nuclei of certain isotopes spontaneously change or are made to change into nuclei of different isotopes

Nuclear change in which unstable isotopes spontaneously emit fast-moving chunks of matter (alpha or beta particles), high-energy radiation (gamma rays), or both at a fixed rate

Unstable isotopes

The time needed for one-half of the nuclei in a given quantity of a radioisotope to decay and emit their radiation to form a different isotope

• Nuclear change in which the nuclei of certain isotopes with large mass numbers are split apart into lighter nuclei when struck by neutrons
• Releases two or three more neutrons plus energy

Amount of fissionable nuclei needed to sustain a nuclear fission chain reaction

• Produced by multiple fissions within a critical mass
• Releases an enormous amount of energy

Nuclear change in which two isotopes of light elements are forced together at extremely high temperatures until they fuse to form a heavier nucleus

The ability to do work and transfer heat

Moving energy

The total kinetic energy of all moving atoms, ions, or molecules within a given substance, excluding the overall motion of the whole object

Kinetic energy that travels in the form of a wave as a result of the changes in electric and magnetic fields

Energy is stored and potentially available for use

Measure of an energy source's ability to do useful work

• Concentrated
• Can perform much useful work

• Dispersed
• Has little ability to do useful work

Ina ll physical and chemical changes, energy is neither created nor destroyed, although it may be converted from one form to another

When energy changes from one form to another, some of the useful energy is always degraded to lower-quality, more dispersed, less useful energy

Measure of how much useful work is accomplished by a particular input of energy into a system

Attempt to boost economic growth by increasing the one-way flow of matter and energy resources through their economic systems

Mimics nature by recycling and reusing most of our matter outputs instead of dumping them into the environment

Economy based on working with nature by recycling and reusing discarded matter