CHEMISTRY GLOSSARY

formula    →   formula

See Chemical compound formula

fusion    →   fuzija

Fusion is nuclear reaction in which atomic nuclei are brought together into a larger nucleus, releasing a large amount of energy. It is also used in the production of hydrogen bombs.

geochemistry    →   geokemija

Geochemistry is the scientific study of the chemical composition of the Earth. It includes the study of the abundance of the Earth’s elements and their isotopes and the distribution of the elements in environments of the Earth (lithosphere, atmosphere, biosphere, and hydrosphere).

dioxin    →   dioksin

Dioxin is a general term that describes a group of hundreds of chemicals that are highly persistent in the environment. The most toxic compound is 2,3,7,8-tetrachlorodibenzo-p-dioxin or TCDD. The toxicity of other dioxins and chemicals like PCBs that act like dioxin are measured in relation to TCDD. Dioxin is formed as an unintentional by-product of many industrial processes involving chlorine such as waste incineration, chemical and pesticide manufacturing and pulp and paper bleaching. Dioxin was the primary toxic component of Agent Orange, found at Love Canal in Niagara Falls, NY and was the basis for evacuations at Times Beach, MO and Seveso, Italy.

Dioxin is formed by burning chlorine-based chemical compounds with hydrocarbons. The major source of dioxin in the environment comes from waste-burning incinerators of various sorts and also from backyard burn-barrels. Dioxin pollution is also affiliated with paper mills which use chlorine bleaching in their process, with the production of Polyvinyl Chloride (PVC) plastics, and with the production of certain chlorinated chemicals (like many pesticides).

gray    →   grej

Gray (Gy) is the SI derived unit of absorbed dose of radiation. The gray is the absorbed dose when the energy per unit mass imparted to matter by ionising radiation is one joule per kilogram (Gy = J/kg). The unit was named after the British scientist Louis Harold Gray (1905-1965).

heat    →   toplina

Heat is a form of energy associated with and proportional to molecular motion. It can be transferred from one body to another by radiation, conduction, or convection.

heat transfer    →   prijenos topline

From observations and experiments it has been found that heat energy can be transferred from one position to another through three different modes: conduction, convection and radiation.

ecological footprint    →   ekološki otisak

The Ecological Footprint is defined as the area of productive land and water ecosystems required to produce the resources that the population consumes (food, fiber, timber, energy, and space for infrastructure) and assimilate the wastes that the population produces (CO₂ is the only waste product currently included), wherever on Earth the land and water is located. It compares actual throughput of renewable resources relative to what is annually renewed. Non-renewable resources are not assessed, as by definition their use is not sustainable.

Ecological footprints and biocapacity are expressed in global hectares (gha). Each unit corresponds to one hectare of biologically productive space with world average productivity. In U.S. Footprint results are often presented in global acres (ga). One U.S. acre is equal to 0.405 hectares.

Humanity is currently consuming renewable resources at a faster rate than ecosystems can regenerate them and continuing to release more CO₂ than ecosystems can absorb. In 2007, humanity's Footprint was 18 billion gha, or 2.7 gha per person. However, the Earth's biocapacity was only 11.9 billion gha, or 1.8 gha per person. This represents an ecological overshoot of 50 per cent. Put another way, people used the equivalent of 1.5 planets to support their activities (more developed countries generally make higher demands on the Earth's ecosystems than poorer, less developed countries).

Einstein equation    →   Einsteinova jednadžba

Einstein equation is the mass-energy relationship introduced by Albert Einstein in 1905 in the form E = mc², where E is a quantity of energy, m its mass, and c is the speed of light. It presents the concept that energy possesses mass.

Einstein, Albert    →   Einstein, Albert

Albert Einstein (1879-1955) is a German born American physicist, who took Swiss nationality in 1901. A year later he went to work in the Bern patent office. In 1905. he published five enormously influential papers, one on Brownian movement, one on the photoelectric effect, one on the special theory of relativity, and one on energy and inertia (which included the famous expression E = mc²). In 1915 he published the general theory of relativity, concerned mainly with gravitation. In 1921 he was awarded the Nobel Prize. In 1933, as a Jew, Einstein decided to remain in the USA (where he was lecturing), as Hitler had come to power. For the remainder of his life he sought a unified field theory. In 1939 he informed president Roosevelt that an atom bomb was feasible and that. Germany might be able to make one.