Display of component wavelengths (colours) of electromagnetic radiation.
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Calibration standards, performance audits, and the FDA's never-ending safety, labeling, and inspection requirements are just the tip of the iceberg when it comes to dealing with the increasingly stringent quality control standards of the beverage industry. As these quality standards become...
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Diamonds are still a girl's best friend, right? We love the shiny gems. They are the most popular rocks sold today. But what exactly are they, anyway? Where do they come from? What else are they used for?
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People use chemicals every day for a wide array of purposes, which can include work and house hold duties. Many of us fail to realize that we are actually handling potentially deadly chemicals when we simply clean the bathroom or wash the car. This brings to mind the reason why chemical safety is...
- Features of the Scanning Tunneling Microscope
The scanning tunneling microscope (STM) invented by Heinrich Rohrer and Gerd Binnig in the 1980s still manages to do a great job today and competes with more advanced microscope types. The scanning tunneling microscope is used for studying the surface atoms that are found on various materials. The...
Coordinate Covalent Bond
A covalent bond in which both shared electrons are donated by the same atom, a bond between a Lewis base and a Lewis acid.
The amount of energy absorbed in the process in which an electron is added to a neutral isolated gaseous atom to form a gaseous ion with a 1- charge, has a negative value if energy is released.
Vaporization of a liquid below its boiling point.
Combination of symbols that indicates the chemical composition of a substance.
Discovered : by Sir William Ramsay in London, and independently by P.T. Cleve and N.A. Langlet in Uppsala, Sweden in 1895.
Origin : The name is derived from the Greek ‘helios’,sun.
Description :A colourless, odourless gas that is totally unreactive. It is extracted from natural gas wells, some of which contain gas that is 7% helium. It is used in deep sea diving for balloons and, as liquid helium, for low temperature research. The Earth’s atmosphere contains 5 parts per million by volume, totalling 400 million tons, but it is not worth extracting it from this source at present.
Atomic No:2 MAss No:4
A very slightly soluble compound.
The quantity of product formed by the interaction of two or more substances, generally expressed as a percentage of the quantity obtained to that theoretically obtainable.
Refers to an optically active substance that rotates the plane of plane polarized light counterclockwise, also called levo.
Symbol for an atom A/Z E, in which E is the symbol of an element, Z is its atomic number, and A is its mass number.
A compound that can be imagined to arise from a partent compound by replacement of one atom with another atom or group of atoms. Used extensively in orgainic chemistry to assist in identifying compounds.
Very weak and very short-range attractive forces between short-lived temporary (induced) dipoles, also called dispersion Forces.
A gas filled tube which discharges electriaclly when ionizing radiation passes through it.
Compounds containing predominantly covalent bonds.
The sequence of steps by which reactants are converted into products.
Aufbau ('building up') Principle
Describes the order in which electrons fill orbitals in atoms.
Photochemically produced oxidizing agents capable of causing damage to plants and animals.
A device used to measure the heat transfer between system and surroundings.
The number (6.022x10^23) of atoms, molecules or particles found in exactly 1 mole of substance.
The mass action expression under any set of conditions (not necessarily equlibrium), its magnitude relative to K determines the direction in which the reaction must occur to establish equilibrium.
Rate of Reaction
Change in the concentration of a reactant or product per unit time.