CHEMISTRY GLOSSARY

thermit welding    →   termitno zavarivanje

Thermit welding is a group of welding processes in which fusion is produced by heating with superheated liquid metal resulting from a chemical reaction between a metal oxide and aluminium.

thermochemistry    →   termokemija

Termochemistry is the study of heat absorbed or released during chemical changes.

thermodynamics    →   termodinamika

Thermodynamics is the scientific study of the interconversion of heat and other forms of energy.

zero law of thermodynamics    →   nulti zakon termodinamike

Zero law of thermodynamics states: If some body A is in thermal equilibrium with body B and with body C, then bodies B and C are also in thermal equilibrium.

Peclet number    →   Pecletova značajka

Péclet number (Pe) is a dimensionless quantity used in fluid mechanics, defined by

where v is velocity, l is length, and a is thermal diffussivity.

plastic    →   plastika

Plastic is a material that can be shaped by the application of heat or pressure. Most are based on synthetic polymers although some are the product of natural substances (such as cellulose derivatives, but excluding the rubbers.). They are usually light and permanent solids, being also heat and electric isolators. If the materials soften again when reheated, they are said to be thermoplastic. If, after fashioning, they resist further applications of heat, they are said to be thermoset.

potential energy    →   potencijalna energija

Potential energy (E_p) is the energy stored in a body or system as a consequence of its position, shape, or state (this includes gravitation energy, electrical energy, nuclear energy, and chemical energy). Gravitational potential energy is the energy associated with the state of separation between bodies that attracts each other via gravitational force. Elastic potential energy is the energy associated with the state of compression or extension of an elastic object. Thermal energy is associated with the random motions of atoms and molecules in a body.

Prandtl number    →   Prandtlova značajka

Prandtl number (Pr) is a dimensionless quantity used in fluid mechanics, defined by

where η is viscosity, ρ is density, and a is thermal diffusivity.

Rayleigh number    →   Rayleighova značajka

Rayleigh number (Ra) is a dimensionless quantity used in fluid mechanics, defined by

where l is length, g is acceleration of gravity, α is cubic expansion coefficient, T is temperature, ρ is density, η is viscosity, and a is thermal diffusivity.

silver    →   srebro

Silver has been known since ancient times. The origin of the name comes from the Latin word argentum meaning silver. It is silvery-ductile and malleable metal. Stable in water and oxygen. Reacts with sulfur compounds to form black sulfides. Silver is found in ores called argentite (AgS), light ruby silver (Ag₃AsS₃), dark ruby silver (Ag₃SbS₃) and brittle silver. Used in alloys for jewellery and in other compounds for photography. It is also a good conductor, but expensive.