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Refers to an optically active substance that rotates the plane of plane polarized light counterclockwise, also called levo.

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Accuracy

How closely a measured value agrees with the correct value.

Iron

Discovered : known to ancient civilisations.

Origin : The name comes from the Anglo-Saxon ‘iren’, and the symbol from the Latin ‘ferrum’, meaning iron.
Description :Iron is an enigma - it rusts easily and yet is the most important of all metals, world production exceeds 700 million tons a year. Small amounts of carbon are added to iron to produce steel and when chromium.
is added to this, the result is non-corroding stainless steel (small amounts of nickel may also be added). Iron is also an essential element for all forms of life. The average human contains about 4 grams, much of which circulates as haemoglobin in the blood, the job of which is to carry oxygen from our lungs to where it is needed. If the diet does not contain 10 milligrams a day, anaemia will eventually develop. Foods such as liver, kidney, molasses, brewer’s yeast, cocoa and liquorice contain a lot of iron.
Atomic No:26 Mass No:56

Absolute Entropy (of a substance)

The increase in the entropy of a substance as it goes from a perfectly ordered crystalline form at 0 °K (where its entropy is zero) to the temperature in question.

Entropy is a measure of the “dilution” of thermal energy.

Valence Shell Electron Pair Repulsion Theory

Assumes that electron pairs are arranged around the central element of a molecule or polyatomic ion so that there is maximum separation (and minimum repulsion) among regions of high electron density.

 

Harmful Chemicals Found In Food

It's getting close to New Years and many people are starting to think about how to lose those extra pounds they managed to gain over the holidays. There are many sorts of diets and fads that have developed over the years from cutting carbs to cutting protein. Everyone has their own opinion as to which one is healthy or not and which produces the best results. There is one thing that almost every can agree on. That being high sugar and caffeine products like sodas are not good for you, but those are not the only dangers found in food and beverages.

Avogadro's Number

The number (6.022x10^23) of atoms, molecules or particles found in exactly 1 mole of substance.

Helium

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

Raoult's Law

The vapor pressure of a solvent in an ideal solution decreases as its mole fraction decreases.

Boiling Point

The temperature at which the vapor pressure of a liquid is equal to the applied pressure, also the condensation point

Dumas Method

A method used to determine the molecular weights of volatile liquids.