... therefore there are many vacancies in valence shell. The crystal lattice of metals consists of ions NOT atoms. When electron clouds overlap, electrons can move into electron cloud of adjoining atoms. The outer electrons (-) from the original metal atoms are free to move around between the positive metal ions formed (+). ... of metal. Copper, for example, is used to make the wire which goes inside electrical cables. Copper is chosen because it can be drawn into long thin wires very easily (it is ductile) and because it is a good conductor of electricity. Metals are also good conductors o...

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... stuff. So here we go. Substance is anything that occupies space and has mass. Substances are diverse: air, water, rock and wood are all substances. Most substances can be broken down into other substances by chemical means. Any substance that cannot be broken down into other substances by ordinary chemical means is called an element. All elements, and thus all substances, are ... - membrane bound sacs, usually containing pigments.  Chloroplasts are a type of plastid that contains a green pigment complex called chlorophyl.  It is the pigment complex that transforms the energy of sunli...

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... a catalyst. Though the resulting material was highly crystalline and of regular structure, it was a black, air-sensitive, infusible and insoluble powder. Ziegler-Natta polymerisation was developed for polymerising alkenes such as ethylene by inserting an unsaturated molecule into the carbon-titanium bond of the growing macromolecule. It depends greatly on the activity of the choice of ... They may possibly find a use in supermarket checkouts. Poly(pyrrole) has been tested as microwave-absorbing "stealth- (radar-invisible) screen coatings and also as the active thin layer of various sen...

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... the bell jar diminished in volume. He found that the air remaining in the ball jar could no longer support either life or combustion. He then heated the red powder, which was converted back into mercury. Moreover, the powder gave off a gas equal in volume to that used ... 66 g of oxygen combine with 1.00 g of carbon. The ratio of these masses is a 2:1 ratio. Dalton definitely turned Democritus's concepts of matter into a scientific theory that could be proved with different experiments. But not everything in Dalton's atomic theory is necessarily correct. In the modern day, we are ... aw...

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... light source material provides a particular form of energy state in which the excited atoms pause before returning to their ground state(metastable state).they remain in this state until stimulated into returning to ground state. Unlike conventional bulbs, which have no mid-energy state(Metastable state). They go from their ground state to the excited state and back again to ... range finders for aircrafts use laser distance meters Laser used for automatic landing systems for aircrafts. Military use of lasers involve the illumination of a target from an aircraft and an air-dropped bomb ...

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