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A thin partition between two solutions through which certain molecules can pass but others cannot.

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  • The most expensive metal in the world

    Do you think the most expensive metal is gold? No! On earth there are more valuable metals. But we need to divide the value of metals that occur in nature, and metals - isotopes, which are obtained in special laboratories. Let’s look at natural metals first.

  • Use of diamonds

    Diamond is a crystalline modification of pure carbon formed in the deep interior of the Earth, in the upper mantle at depths of more than 80-100 kilometers, at exceptionally high pressure and temperature. It is the most precious stone, the hardest and most wear-resistant mineral, the most...

  • What are Compound Microscopes?

    Most of the microscopes used today are compound. A compound microscope features two or more lenses. A hollow cylinder called the tube connects the two lenses. The top lens, the one people look through, is called the eyepiece. The bottom lens is known as the objective lens. Below the two lenses is...

  • Varieties of garnet minerals

    The most famous type of garnet stone is pyrope (flaming). This is the "oldest of garnets", with a dense red color, similar to the grain of an edible garnet. Pyrope has a variety called rhodolite - a stone of dense pink or pink-purple color, which sometimes has the alexandrite effect and is used in...

  • Gas of rotten eggs

    If you happen to break a rotten egg, then you know the smell of hydrogen sulfide, because the stench of the spoiled egg depends on of its presence in rotting protein substances.



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Coulomb

Unit of electrical charge.

Integrated Rate Equation

An equation giving the concentration of a reactant remaining after a specified time, has different mathematical form for different orders of reactants.

Eluate

Solvent (or mobile phase) which passes through a chromatographic column and removes the sample components from the stationary phase.

yttrium metal

Any of a subgroup of rare-earth elements, of which the cerium and terbium metals comprise the other two subgroups.

Supercritical Fluid

A substance at temperature above its critical temperature.

Coordination Isomers

Isomers involving exchanges of ligands between complex cation and complex anion of the same compound.

Actinides

Elements 89 to 103 (between lawrencium and actinium) on the periodic table. Only the first four have been found in nature in appreciable amounts. The remainder have been produced synthetically.

Electromotive Series

The relative order of tendencies for elements and their simple ions to act as oxidizing or reducing agents, also called the activity series.

van der Waals' Equation

An equation of state that extends the ideal gas law to real gases by inclusion of two empirically determined parameters, which are different for different gases.

Functional Group

A group of atoms that represents a potential reaction site in an organic compound.