CHEMISTRY GLOSSARY
living planet index → indeks života na planetu
The Living Planet Index (LPI) reflects changes in the health of the planet's ecosystems by tracking trends in nearly 8000 populations of vertebrate species. The LPI first calculates the annual rate of change for each species population in the dataset, then calculates the average change across all populations for each year from 1970, when data collection began, to 2007, the latest date for which data is available.
The Global LPI shows a decline of around 30 % from 1970 to 2007, based on 7953 populations of 2544 species of birds, mammals, amphibians, reptiles and fish.
mass-energy equivalence → ekvivalencija mase i energije
In the special theory of relativity Einstein demonstrated that neither mass nor energy were conserved separately, but that they could be traded one for the other and only the total "mass-energy" was conserved. The relationship between the mass and the energy is contained in what is probably the most famous equation in science,
Where m is the mass of the object and c is the velocity of light. Cockcroft and Walton (1932) are routinely credited with the first experimental verification of mass-energy equivalence.
mercury → živa
Mercury has been known since ancient times. The origin of the name comes from the Latin word hydrargyrum meaning liquid silver. It is heavy, silver-white metal, liquid at ordinary temperatures. Stable in air and water. Unreactive with alkalis and most acids. Gives off poisonous vapour. Chronic cumulative effects. Mercury only rarely occurs free in nature. The chief ore is cinnabar or mercury sulfide (HgS). Used in thermometers, barometers and batteries. Also used in electrical switches and mercury-vapour lighting products.
weak electrolyte → slabi elektrolit
Weak electrolytes are those electrolytes which in water solutions dissociate only partially, giving ions and which are in equilibrium with undissociated molecules. Their water solutions conduct electric current weakly. For example, acetic acid partially dissociates into acetate ions and hydrogen ions, so that an acetic acid solution contains both molecules and ions.
metal → metal
Metals are materials in which the highest occupied energy band (conduction band) is only partially filled with electrons.
Their physical properties generally include:
- They are good conductors of heat and electricity. The electrical conductivity of metals generally decreases with temperature.
- They are malleable and ductile in their solid state.
- They show metallic lustre.
- They are opaque.
- They have high density.
- They are solids (except mercury)
- They have a crystal structure in which each atom is surrounded by eight to twelve near neighbours
Their chemical properties generally are:
- They have one to four valence electrons.
- They have low ionisation potentials; they readily lose electrons.
- They are good reducing agents.
- They have hydroxides which are bases or amphoteric.
- They are electropositive.
Metallic characteristics of the elements decrease and non-metallic characteristics increase with the increase of valence electrons. Also metallic characteristics increase with the number of electron shells. Therefore, there is no sharp dividing line between the metals and non-metals.
Of the 114 elements now known, only 17 show primarily non-metallic characteristics, 7 others are metalloids, and 89 may be classed as metals.
metallic glass → metalno staklo
Certain alloys can solidify by extremely rapid cooling out of melt without formation of a crystal lattice, that is in the amorphous form - such, amorphous alloys are so called metallic glasses. The alloy of zirconium, beryllium, titanium, copper, and nickel is one of the first metallic glasses that can be made in bulk and formed into strong, hard, useful objects.
Unlike pure metals and most metal alloys, metallic glasses have no regular crystalline structure. This lack of long range order or microstructure is related to such desirable features as strength and low damping which is one reason why the premier use for zirconium-based metallic glass is in the manufacture of expensive golf club heads. Metallic glasses can be quite strong yet highly elastic, and they can also be quite tough (resistant to fracture). Even more interesting are the thermal properties; for instance, just like an oxide glass, there is a temperature (called the glass transition temperature) above which a metallic glass becomes quite soft and flows easily. This means that there are lots of opportunities for easily forming metallic glasses into complex shapes.
Zimmermann-Reinhardt’s reagent → Zimmermann-Reinhardtov reagens
Zimmermann-Reinhardt’s reagent is a mixture of manganese(II) sulphate, sulphuric acid and phosphorus acid. It is used for preventing oxidation of chloride ion while titrating iron(II) ion with permanganate solution.
methionine → metionin
Methionine is neutral amino acids with polar side chains. It is one of the two sulfur-containing amino acids. Methionine is a fairly hydrophobic amino acid and typically found buried within the interior of a protein. It can form stacking interactions with the aromatic moieties of tryptophan, phenylalanine, and tyrosine. It is an essential amino acid, which means that humans cannot synthesize it, so it must be ingested.
- Abbreviations: Met, M
- IUPAC name: 2-amino-4-methylsulfanylbutanoic acid
- Molecular formula: C5H11NO2S
- Molecular weight: 149.21 g/mol
Citing this page:
Generalic, Eni. "Bronsted-Lowry’s acid - base theory." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
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