Tin has been known since ancient times. The origin of the name comes from the Latin word stannum meaning tin. It is silvery-white, soft, malleable and ductile metal. Exposed surfaces form oxide film. Resists oxygen and water. Dissolves in acids and bases. Organic tin compounds may be highly toxic. Tin is principally found in the ore cassiterite (SnO2) and stannine (Cu2FeSnS4). Used as a coating for steel cans since it is non-toxic and non-corrosive. Also in solder (33 %Sn:67 %Pb), bronze (20 %Sn:80 %Cu) and pewter. Stannous fluoride (SnF2), a compound of tin and fluorine is used in some toothpaste.
Triclinic lattice has one lattice point at the each corner of the unit cell. It has unit cell vectors a≠b≠c and interaxial angles α≠β≠γ≠90°.
Unsaturated fats, which include one or more unsaturated fatty acid, are liquid at room temperature (oil) and come from plant oils such as olive, peanut, corn, sunflower, safflower, and soybean. The fish oils may also be high in unsaturated fatty acids.
Human eye can only see electromagnetic radiation of wavelengths form 400 nm to 760 nm. This narrow part of electromagnetic spectrum is called visible radiation. Visible (white) light is a mixture of light of all kind of colours, it can be separated, with the help of a glass prism, into its component colours - visible light spectrum, and each colour corresponds to a certain area of wavelengths:
Colour | Wavelength / nm |
---|---|
purple | 400 - 450 |
blue | 450 - 500 |
green | 500 - 570 |
yellow | 570 - 590 |
orange | 590 - 620 |
red | 620 - 760 |
Wire mesh (wire gauze) is used for uniform distribution of flame heat in base of a heated body. It is made of a iron wire strands with or without ceramic interior cores.
Zirconium was discovered by Martin Heinrich Klaproth (Germany) in 1789. The origin of the name comes from the Arabic word zargun meaning gold colour. It is grey-white, lustrous, corrosion-resistant metal. Exposed surfaces form oxide protective film. Zirconium is found in many minerals such as zircon and baddeleyite. Used in alloys such as zircaloy this is used in nuclear applications since it does not readily absorb neutrons. Also baddeleyite is used in lab crucibles. Used in high-performance pumps and valves. Clear zircon (ZrSiO4) is a popular gemstone.
Absorbance (A) is a logarithm of the ratio of incident radiant power (Po) to transmitted radiant power (P) through a sample (excluding the effects on cell walls).
The absorption of light by a substance in a solution can be described mathematically by the Beer-Lambert law
where A is the absorbance at a given wavelength of light, ε is the molar absorbtivity or extinction coefficient (L mol-1 cm-1), unique to each molecule and varying with wavelength, b is the length of light path through the sample (cm), and c is the concentration of the compound in solution (mol L-1).
Absorption is a phenomenon that occurs when matter crosses from one phase to another passing through the border surface and in the other phase more or less monotonously distributes itself in a concentration higher than the one within the first phase.
Elements in nature are mostly found in different compounds and, rarely, in the free (elementary) state. In Earth’s crust the most abundant of all elements is oxygen (with 49.5 %), then silicon (25 %), aluminium (7.5 %), iron (4.7 %), calcium (3.4 %), sodium (2.6 %), potassium (2.4 %), magnesium (1.9 %) and hydrogen (1.9 %). These nine elements make up almost 99 % of the Earth’s composition.
Generalic, Eni. "High fructose corn syrup." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
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Periodic Table