text
stringlengths
2
2.33k
source
stringclasses
826 values
gamma ray : (γor00γ)00γ)short wavelength, high-energy electromagnetic radiation that exhibits wave-particle duality
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
Geiger counter : instrument that detects and measures radiation via the ionization produced in a Geiger-Müller tube
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
gray (Gy) : SI unit for measuring radiation dose; 1 Gy = 1 J absorbed/kg tissue
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
half-life (t1/2) : time required for half of the atoms in a radioactive sample to decay
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
internal radiation therapy : (also, brachytherapy) radiation from a radioactive substance introduced into the body to kill cancer cells
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
ionizing radiation : radiation that can cause a molecule to lose an electron and form an ion
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
magic number : nuclei with specific numbers of nucleons that are within the band of stability
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
mass defect : difference between the mass of an atom and the summed mass of its constituent subatomic particles (or the mass “lost” when nucleons are brought together to form a nucleus)
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
mass-energy equivalence equation : Albert Einstein’s relationship showing that mass and energy are equivalent
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
millicurie (mCi) : larger unit for rate of radioactive decay frequently used in medicine; 1 Ci = 3.7××1010disintegrations/s
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
nonionizing radiation : radiation that speeds up the movement of atoms and molecules; it is equivalent to heating a sample, but is not energetic enough to cause the ionization of molecules
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
nuclear binding energy : energy lost when an atom’s nucleons are bound together (or the energy needed to break a nucleus into its constituent protons and neutrons)
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
nuclear chemistry : study of the structure of atomic nuclei and processes that change nuclear structure
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
nuclear fuel : fissionable isotope present in sufficient quantities to provide a self-sustaining chain reaction in a nuclear reactor
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
nuclear moderator : substance that slows neutrons to a speed low enough to cause fission
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
nuclear reaction : change to a nucleus resulting in changes in the atomic number, mass number, or energy state
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
nuclear reactor : environment that produces energy via nuclear fission in which the chain reaction is controlled and sustained without explosion
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
nuclear transmutation : conversion of one nuclide into another nuclide
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
nucleon : collective term for protons and neutrons in a nucleus
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
nuclide : nucleus of a particular isotope
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
parent nuclide : unstable nuclide that changes spontaneously into another (daughter) nuclide
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
particle accelerator : device that uses electric and magnetic fields to increase the kinetic energy of nuclei used in transmutation reactions
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
positron(+10β(+10βor+10e)+10e) : antiparticle to the electron; it has identical properties to an electron, except for having the opposite (positive) charge
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
positron emission : (also, β+decay) conversion of a proton into a neutron, which remains in the nucleus, and a positron, which is emitted
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
radiation absorbed dose (rad) : SI unit for measuring radiation dose, frequently used in medical applications; 1 rad = 0.01 Gy
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
radiation dosimeter : device that measures ionizing radiation and is used to determine personal radiation exposure
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
radiation therapy : use of high-energy radiation to damage the DNA of cancer cells, which kills them or keeps them from dividing
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
radioactive decay : spontaneous decay of an unstable nuclide into another nuclide
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
radioactive decay series : chains of successive disintegrations (radioactive decays) that ultimately lead to a stable end-product
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
radioactive tracer : (also, radioactive label) radioisotope used to track or follow a substance by monitoring its radioactive emissions
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
radioactivity : phenomenon exhibited by an unstable nucleon that spontaneously undergoes change into a nucleon that is more stable; an unstable nucleon is said to be radioactive
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
radiocarbon dating : highly accurate means of dating objects 30,000–50,000 years old that were derived from once-living matter; achieved by calculating the ratio of614C:612C614C:612Cin the object vs. the ratio of614C:612C614C:612Cin the present-day atmosphere
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
radioisotope : isotope that is unstable and undergoes conversion into a different, more stable isotope
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
radiometric dating : use of radioisotopes and their properties to date the formation of objects such as archeological artifacts, formerly living organisms, or geological formations
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
reactor coolant : assembly used to carry the heat produced by fission in a reactor to an external boiler and turbine where it is transformed into electricity
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
relative biological effectiveness (RBE) : measure of the relative damage done by radiation
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
roentgen equivalent man (rem) : unit for radiation damage, frequently used in medicine; 100 rem = 1 Sv
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
scintillation counter : instrument that uses a scintillator—a material that emits light when excited by ionizing radiation—to detect and measure radiation
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
sievert (Sv) : SI unit measuring tissue damage caused by radiation; takes into account energy and biological effects of radiation
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
strong nuclear force : force of attraction between nucleons that holds a nucleus together
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
subcritical mass : amount of fissionable material that cannot sustain a chain reaction; less than a critical mass
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
supercritical mass : amount of material in which there is an increasing rate of fission
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
transmutation reaction : bombardment of one type of nuclei with other nuclei or neutrons
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
transuranium element : element with an atomic number greater than 92; these elements do not occur in nature
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-key-terms
An atomic nucleus consists of protons and neutrons, collectively called nucleons. Although protons repel each other, the nucleus is held tightly together by a short-range, but very strong, force called the strong nuclear force. A nucleus has less mass than the total mass of its constituent nucleons. This “missing” ...
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-summary
Nuclei can undergo reactions that change their number of protons, number of neutrons, or energy state. Many different particles can be involved in nuclear reactions. The most common are protons, neutrons, positrons (which are positively charged electrons), alpha (α) particles (which are high-energy helium nuclei), bet...
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-summary
Nuclei that have unstable n:p ratios undergo spontaneous radioactive decay. The most common types of radioactivity are α decay, β decay, γ emission, positron emission, and electron capture. Nuclear reactions also often involve γ rays, and some nuclei decay by electron capture. Each of these modes of decay leads to ...
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-summary
It is possible to produce new atoms by bombarding other atoms with nuclei or high-speed particles. The products of these transmutation reactions can be stable or radioactive. A number of artificial elements, including technetium, astatine, and the transuranium elements, have been produced in this way.
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-summary
Nuclear power as well as nuclear weapon detonations can be generated through fission (reactions in which a heavy nucleus is split into two or more lighter nuclei and several neutrons). Because the neutrons may induce additional fission reactions when they combine with other heavy nuclei, a chain reaction can result. Us...
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-summary
Compounds known as radioactive tracers can be used to follow reactions, track the distribution of a substance, diagnose and treat medical conditions, and much more. Other radioactive substances are helpful for controlling pests, visualizing structures, providing fire warnings, and for many other applications. Hundreds ...
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-summary
We are constantly exposed to radiation from a variety of naturally occurring and human-produced sources. This radiation can affect living organisms. Ionizing radiation is the most harmful because it can ionize molecules or break chemical bonds, which damages the molecule and causes malfunctions in cell processes. It ca...
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-summary
Various devices, including Geiger counters, scintillators, and dosimeters, are used to detect and measure radiation, and monitor radiation exposure. We use several units to measure radiation: becquerels or curies for rates of radioactive decay; gray or rads for energy absorbed; and rems or sieverts for biological effec...
https://openstax.org/books/chemistry-atoms-first-2e/pages/20-summary
addition reaction : reaction in which a double carbon-carbon bond forms a single carbon-carbon bond by the addition of a reactant. Typical reaction for an alkene.
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
alcohol : organic compound with a hydroxyl group (–OH) bonded to a carbon atom
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
aldehyde : organic compound containing a carbonyl group bonded to two hydrogen atoms or a hydrogen atom and a carbon substituent
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
alkane : molecule consisting of only carbon and hydrogen atoms connected by single (σ) bonds
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
alkene : molecule consisting of carbon and hydrogen containing at least one carbon-carbon double bond
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
alkyl group : substituent, consisting of an alkane missing one hydrogen atom, attached to a larger structure
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
alkyne : molecule consisting of carbon and hydrogen containing at least one carbon-carbon triple bond
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
amide : organic molecule that features a nitrogen atom connected to the carbon atom in a carbonyl group
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
amine : organic molecule in which a nitrogen atom is bonded to one or more alkyl group
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
aromatic hydrocarbon : cyclic molecule consisting of carbon and hydrogen with delocalized alternating carbon-carbon single and double bonds, resulting in enhanced stability
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
carbonyl group : carbon atom double bonded to an oxygen atom
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
carboxylic acid : organic compound containing a carbonyl group with an attached hydroxyl group
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
ester : organic compound containing a carbonyl group with an attached oxygen atom that is bonded to a carbon substituent
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
ether : organic compound with an oxygen atom that is bonded to two carbon atoms
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
functional group : part of an organic molecule that imparts a specific chemical reactivity to the molecule
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
ketone : organic compound containing a carbonyl group with two carbon substituents attached to it
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
organic compound : natural or synthetic compound that contains carbon
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
saturated hydrocarbon : molecule containing carbon and hydrogen that has only single bonds between carbon atoms
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
skeletal structure : shorthand method of drawing organic molecules in which carbon atoms are represented by the ends of lines and bends in between lines, and hydrogen atoms attached to the carbon atoms are not shown (but are understood to be present by the context of the structure)
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
substituent : branch or functional group that replaces hydrogen atoms in a larger hydrocarbon chain
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
substitution reaction : reaction in which one atom replaces another in a molecule
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-key-terms
Strong, stable bonds between carbon atoms produce complex molecules containing chains, branches, and rings. The chemistry of these compounds is called organic chemistry. Hydrocarbons are organic compounds composed of only carbon and hydrogen. The alkanes are saturated hydrocarbons—that is, hydrocarbons that contain o...
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-summary
Many organic compounds that are not hydrocarbons can be thought of as derivatives of hydrocarbons. A hydrocarbon derivative can be formed by replacing one or more hydrogen atoms of a hydrocarbon by a functional group, which contains at least one atom of an element other than carbon or hydrogen. The properties of hydroc...
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-summary
Functional groups related to the carbonyl group include the –CHO group of an aldehyde, the –CO– group of a ketone, the –CO2H group of a carboxylic acid, and the –CO2R group of an ester. The carbonyl group, a carbon-oxygen double bond, is the key structure in these classes of organic molecules: Aldehydes conta...
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-summary
The addition of nitrogen into an organic framework leads to two families of molecules. Compounds containing a nitrogen atom bonded in a hydrocarbon framework are classified as amines. Compounds that have a nitrogen atom bonded to one side of a carbonyl group are classified as amides. Amines are a basic functional group...
https://openstax.org/books/chemistry-atoms-first-2e/pages/21-summary
accuracy : the degree to which a measured value agrees with correct value for that measurement
https://openstax.org/books/college-physics-2e/pages/1-glossary
approximation : an estimated value based on prior experience and reasoning
https://openstax.org/books/college-physics-2e/pages/1-glossary
classical physics : physics that was developed from the Renaissance to the end of the 19th century
https://openstax.org/books/college-physics-2e/pages/1-glossary
conversion factor : a ratio expressing how many of one unit are equal to another unit
https://openstax.org/books/college-physics-2e/pages/1-glossary
derived units : units that can be calculated using algebraic combinations of the fundamental units
https://openstax.org/books/college-physics-2e/pages/1-glossary
English units : system of measurement used in the United States; includes units of measurement such as feet, gallons, and pounds
https://openstax.org/books/college-physics-2e/pages/1-glossary
fundamental units : units that can only be expressed relative to the procedure used to measure them
https://openstax.org/books/college-physics-2e/pages/1-glossary
kilogram : the SI unit for mass, abbreviated (kg)
https://openstax.org/books/college-physics-2e/pages/1-glossary
law : a description, using concise language or a mathematical formula, a generalized pattern in nature that is supported by scientific evidence and repeated experiments
https://openstax.org/books/college-physics-2e/pages/1-glossary
meter : the SI unit for length, abbreviated (m)
https://openstax.org/books/college-physics-2e/pages/1-glossary
method of adding percents : the percent uncertainty in a quantity calculated by multiplication or division is the sum of the percent uncertainties in the items used to make the calculation
https://openstax.org/books/college-physics-2e/pages/1-glossary
metric system : a system in which values can be calculated in factors of 10
https://openstax.org/books/college-physics-2e/pages/1-glossary
model : representation of something that is often too difficult (or impossible) to display directly
https://openstax.org/books/college-physics-2e/pages/1-glossary
modern physics : the study of relativity, quantum mechanics, or both
https://openstax.org/books/college-physics-2e/pages/1-glossary
order of magnitude : refers to the size of a quantity as it relates to a power of 10
https://openstax.org/books/college-physics-2e/pages/1-glossary
percent uncertainty : the ratio of the uncertainty of a measurement to the measured value, expressed as a percentage
https://openstax.org/books/college-physics-2e/pages/1-glossary
physical quantity : a characteristic or property of an object that can be measured or calculated from other measurements
https://openstax.org/books/college-physics-2e/pages/1-glossary
physics : the science concerned with describing the interactions of energy, matter, space, and time; it is especially interested in what fundamental mechanisms underlie every phenomenon
https://openstax.org/books/college-physics-2e/pages/1-glossary
precision : the degree to which repeated measurements agree with each other
https://openstax.org/books/college-physics-2e/pages/1-glossary
quantum mechanics : the study of objects smaller than can be seen with a microscope
https://openstax.org/books/college-physics-2e/pages/1-glossary
relativity : the study of objects moving at speeds greater than about 1% of the speed of light, or of objects being affected by a strong gravitational field
https://openstax.org/books/college-physics-2e/pages/1-glossary
scientific method : a method that typically begins with an observation and question that the scientist will research; next, the scientist typically performs some research about the topic and then devises a hypothesis; then, the scientist will test the hypothesis by performing an experiment; finally, the scientist analy...
https://openstax.org/books/college-physics-2e/pages/1-glossary
second : the SI unit for time, abbreviated (s)
https://openstax.org/books/college-physics-2e/pages/1-glossary