| Temperature |
The measure, on any of several scales, of the average kinetic
energy of the molecules in a sample of material |
| Temperature Inversion |
The abnormal condition of a layer of warm air above cooler
surface air |
| Tempering |
a process in steel production that fine-tunes the proportions
of carbon crystals and cementite by heating to intermediate temperatures followed by rapid
cooling |
| Termination Step |
A step in a chain reaction mechanism that does not produce an
intermediate reactant needed for a propagation step |
| Termolecular Elementary Process |
An elementary process in which three molecules collide to
form the transition state |
| Tertiary structure (of a protein) |
the overall shape of a protein, long and narrow or globular,
maintained by different types of intrarnolecular interactions |
| Tetrahedron |
A three-dimensional geometric figure having four triangular
sides |
| Theoretical yield |
the maximum amount of a given product that can be formed when
the limiting reactant is completely consumed |
| Theory |
A plausible general principle or group of principles offered
in terms of a model to explain phenomena |
| Thermal Energy |
The energy in a body that is measured with a thermometer |
| Thermal pollution |
the oxygen-depleting effect on lakes and rivers of using
water for industrial cooling and returning it to its natural source at a higher
temperature |
| Thermochemical Equation |
A chemical equation showing the enthalpy change for a
reaction involving reactants and products in specified states |
| Thermodynamics |
the study of energy and its interconversions |
| Thermodynamic stability (nuclear) |
the potential energy of a particular nucleus as compared to
the sum of the potential energies of its component protons and neutrons |
| Thermodynamically Reversible |
Referring to the condition in which a process can be caused
to proceed in the reverse direction by an infinitesimal change of conditions such as
temperature, pressure, or concentration |
| Thermonuclear Reaction |
A nuclear fusion reaction occurring at extremely high
temperatures |
| Thermoplastic polymer |
a substance that when molded to a certain shape under
appropriate conditions can later be remelted |
| Thermoset polymer |
a substance that when molded to a certain shape under
pressure and high temperatures cannot be softened again or dissolved |
| Third law of thermodynamics |
the entropy of a perfect crystal at 0 K is zero |
| Titration |
The measurement of the volume of a solution of known
concentration required to react completely with an unknown quantity of another substance |
| Titration Curve |
A plot of pH versus the volume of reactant added during an
acid-base titration |
| Torr |
another name for millimeter of mercury (mm Hg) |
| Trace elements |
metals present only in trace amounts in the human body but
essential for the action of many enzymes |
| Transfer RNA (tRNA) |
a small RNA fragment that finds specific amino acids and
attaches them to the protein chain as dictated by the codons in mRNA |
| Transition Metals |
Elements of the B groups of the periodic table d block |
| Transition State |
The state through which reactants pass during an effective
collision and in which bonds simultaneously break and form to produce the products also
called activated complex |
| Transuranium Elements |
Elements with atomic numbers greater than that of uranium |
| Triangular Pyramid |
A pyramid with a triangular base |
| Triangular Bipyramid |
A geometric figure having six triangular faces |
| Triangular Geometry |
A term describing a triangular shape or, more specifically, a
molecule having a central atom surrounded by three other atoms, all in the same plane |
| Triple Bond |
bond in which three pairs of electrons are shared by two
atoms |
| Triple point |
the point on a phase diagram at which all three states of a
substance are present |
| Triplet |
An electron energy state in which two electrons are unpaired |
| Tyndall effect |
the scattering of light by particles in a suspension |
