Science, Grades 9-12 141 words

a pedal that controls the throttle valve

(meteorology) the horizontal transfer of heat or other atmospheric properties

physicist born in Germany who formulated the special theory of relativity and the general theory of relativity; Einstein also proposed that light consists of discrete quantized bundles of energy (later called photons) (1879-1955)

French chemist known as the father of modern chemistry; discovered oxygen and disproved the theory of phlogiston (1743-1794)

a nuclear weapon in which enormous energy is released by nuclear fission (splitting the nuclei of a heavy element like uranium 235 or plutonium 239)

the energy released by a nuclear reaction

(chemistry) the mass of an atom of a chemical element expressed in atomic mass units

the order of an element in Mendeleyev's table of the elements; equal to the number of protons in the nucleus or electrons in the neutral state of an atom of an element

a theory of the structure of the atom

(chemistry) the mass of an atom of a chemical element expressed in atomic mass units

(cosmology) the theory that the universe originated sometime between 10 billion and 20 billion years ago from the cataclysmic explosion of a small volume of matter at extremely high density and temperature

the branch of molecular biology that studies the use of microorganisms to perform specific industrial processes

a small piece or quantity of something

a sequence of 8 bits (enough to represent one character of alphanumeric data) processed as a single unit of information

an abundant nonmetallic tetravalent element occurring in three allotropic forms: amorphous carbon and graphite and diamond; occurs in all organic compounds

an atom of carbon

the organic circulation of carbon from the atmosphere into organisms and back again

a heavy odorless colorless gas formed during respiration and by the decomposition of organic substances; absorbed from the air by plants in photosynthesis

a thin membrane (a double layer of lipids) enclosing the cytoplasm of a cell; proteins in the membrane control passage of ions (like sodium or potassium or calcium) in and out of the cell

a part of the cell containing DNA and RNA and responsible for growth and reproduction

a specialized part of a cell; analogous to an organ

a rigid layer of polysaccharides enclosing the membrane of plant and prokaryotic cells; maintains the shape of the cell and serves as a protective barrier

English natural scientist who formulated a theory of evolution by natural selection (1809-1882)

a site on the internet where a number of users can communicate in real time (typically one dedicated to a particular topic)

an electrical force linking atoms

a small fragment of something broken off from the whole

plastid containing chlorophyll and other pigments; in plants that carry out photosynthesis

a process used for separating mixtures by virtue of differences in absorbency

a threadlike strand of DNA in the cell nucleus that carries the genes in a linear order

a control system with a feedback loop that is active

the transfer of heat through a fluid (liquid or gas) caused by molecular motion

Polish astronomer who produced a workable model of the solar system with the sun in the center (1473-1543)

(computer science) the part of a computer (a microprocessor chip) that does most of the data processing

the protoplasm of a cell excluding the nucleus; is full of proteins that control cell metabolism

locate and correct errors in a computer program code

(biochemistry) a long linear polymer found in the nucleus of a cell and formed from nucleotides and shaped like a double helix; associated with the transmission of genetic information

change in the apparent frequency of a wave as observer and source move toward or away from each other

pull, as against a resistance

the tendency of a body to return to its original shape after it has been stretched or compressed

a motor that converts electricity to mechanical work

the difference in electrical charge between two points in a circuit expressed in volts

radiation consisting of waves of energy associated with electric and magnetic fields resulting from the acceleration of an electric charge

the entire frequency range of electromagnetic waves

radiation consisting of waves of energy associated with electric and magnetic fields resulting from the acceleration of an electric charge

an elementary particle with negative charge

(physics) a particle that is less complex than an atom; regarded as constituents of all matter

a chemical reaction accompanied by the absorption of heat

Italian nuclear physicist (in the United States after 1939) who worked on artificial radioactivity caused by neutron bombardment and who headed the group that in 1942 produced the first controlled nuclear reaction (1901-1954)

(communication theory) a numerical measure of the uncertainty of an outcome

any of several complex proteins that are produced by cells and act as catalysts in specific biochemical reactions

British physicist (born in New Zealand) who discovered the atomic nucleus and proposed a nuclear model of the atom (1871-1937)

a chemical reaction accompanied by the evolution of heat

the use of controlled observations and measurements to test hypotheses

a data storage device that is not the main memory of a computer

of or relating to a temperature scale proposed by the inventor of the mercury thermometer

extensive tract of level open land

the internal supporting structure that gives an artifact its shape

electromagnetic radiation emitted during radioactive decay and having an extremely short wavelength

conversion of the information encoded in a gene first into messenger RNA and then to a protein

a generalization of special relativity to include gravity (based on the principle of equivalence)

(genetics) any event that changes genetic structure; any alteration in the inherited nucleic acid sequence of the genotype of an organism

the time of the physical formation and development of the earth (especially prior to human history)

use of chemical analysis to estimate the age of geological specimens

(medicine) the theory that all contagious diseases are caused by microorganisms

a unit of information equal to 1000 megabytes or 10^9 (1,000,000,000) bytes

a netlike structure in the cytoplasm of animal cells (especially in those cells that produce secretions)

a gas that contributes to the greenhouse effect by absorbing infrared radiation

Augustinian monk and botanist whose experiments in breeding garden peas led to his eventual recognition as founder of the science of genetics (1822-1884)

a set of tags and rules (conforming to SGML) for using them in developing hypertext documents

a nuclear weapon that releases atomic energy by union of light (hydrogen) nuclei at high temperatures to form helium

a positively charged atom of hydrogen; that is to say, a normal hydrogen atomic nucleus

assign an initial value to a computer program

a particle that is electrically charged (positive or negative); an atom or molecule or group that has lost or gained one or more electrons

German astronomer who first stated laws of planetary motion (1571-1630)

English chemist and physicist who formulated atomic theory and the law of partial pressures; gave the first description of red-green color blindness (1766-1844)

British physicist who invented the Kelvin scale of temperature and pioneered undersea telegraphy (1824-1907)

a unit of information equal to 1000 bytes

Swedish physicist (born in Austria) who worked in the field of radiochemistry with Otto Hahn and formulated the concept of nuclear fission with Otto Frisch (1878-1968)

very large in scale or scope or capability

the lines of force surrounding a permanent magnet or a moving charged particle

a unit of information equal to 1000 kilobytes or 10^6 (1,000,000) bytes

(genetics) cell division that produces reproductive cells in sexually reproducing organisms; the nucleus divides into four nuclei each containing half the chromosome number (leading to gametes in animals and spores in plants)

integrated circuit semiconductor chip that performs the bulk of the processing and controls the parts of a system

kitchen appliance that cooks food by passing an electromagnetic wave through it; heat results from the absorption of energy by the water molecules in the food

an organelle containing enzymes responsible for producing energy

cell division in which the nucleus divides into nuclei containing the same number of chromosomes

a small congenital pigmented spot on the skin

an object occurring naturally; not made by man

a natural process resulting in the evolution of organisms best adapted to the environment

a cell that is specialized to conduct nerve impulses

a neurochemical that transmits nerve impulses across a synapse

an elementary particle with 0 charge and mass about equal to a proton; enters into the structure of the atomic nucleus

the branch of mechanics based on Newton's laws of motion

a common nonmetallic element that is normally a colorless odorless tasteless inert diatomic gas; constitutes 78 percent of the atmosphere by volume; a constituent of all living tissues

the circulation of nitrogen; nitrates from the soil are absorbed by plants which are eaten by animals that die and decay returning the nitrogen back to the soil

a nuclear reaction in which a massive nucleus splits into smaller nuclei with the simultaneous release of energy

a nuclear reaction in which nuclei combine to form more massive nuclei with the simultaneous release of energy

a unit of electrical resistance equal to the resistance between two points on a conductor when a potential difference of one volt between them produces a current of one ampere

(computer science) software that controls the execution of computer programs and may provide various services

a colorless gas (O3) soluble in alkalis and cold water; a strong oxidizing agent; can be produced by electric discharge in oxygen or by the action of ultraviolet radiation on oxygen in the stratosphere (where it acts as a screen for ultraviolet radiation)

(computer science) electronic equipment connected by cable to the CPU of a computer

involving direct communication or contact between persons or parties

(computer science) the smallest discrete component of an image or picture on a CRT screen (usually a colored dot)

the branch of geology studying the folding and faulting of the earth's crust

the mechanical energy that a body has by virtue of its position; stored energy

any of a large group of nitrogenous organic compounds that are essential constituents of living cells; consist of polymers of amino acids; essential in the diet of animals for growth and for repair of tissues; can be obtained from meat and eggs and milk and legumes

a stable particle with positive charge equal to the negative charge of an electron

Alexandrian astronomer (of the 2nd century) who proposed a geocentric system of astronomy that was undisputed until the late Renaissance

an electromagnetic wave with a wavelength between 0.5 cm to 30,000 m

measurement of the amount of radioactive material (usually carbon 14) that an object contains; can be used to estimate the age of the object

the spontaneous disintegration of a radioactive substance along with the emission of ionizing radiation

the most common computer memory which can be used by programs to perform necessary tasks while the computer is on; an integrated circuit memory chip allows information to be stored or accessed in any order and all storage locations are equally accessible

the attribute of being superfluous and unneeded

someone who scans verse to determine the number and prosodic value of the syllables

a substance as germanium or silicon whose electrical conductivity is intermediate between that of a metal and an insulator; its conductivity increases with temperature and in the presence of impurities

a spermatozoon or an ovum; a cell responsible for transmitting DNA to the next generation

(acoustics) a wave that transmits sound

a rocket-propelled guided missile that can escape the earth's atmosphere; makes observations of the solar system that cannot be made by terrestrial observation

unwanted e-mail (usually of a commercial nature sent out in bulk)

a physical theory of relativity based on the assumption that the speed of light in a vacuum is a constant and the assumption that the laws of physics are invariant in all inertial systems

the evolution of a biological species

the speed at which light travels in a vacuum; the constancy and universality of the speed of light is recognized by defining it to be exactly 299,792,458 meters per second

the circulation of cytoplasm within a cell

a system that is part of some larger system

a model or standard for making comparisons

a state in which all parts of a system are at the same temperature

any agent (person or animal or microorganism) that carries and transmits a disease

radiation lying in the ultraviolet range; wave lengths shorter than light but longer than X rays

a tiny cavity filled with fluid in the cytoplasm of a cell

resistance of a liquid to shear forces (and hence to flow)

take an x-ray of something or somebody