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The number of repeating corresponding points on a wave that pass a given observation point per unit time.

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  • Creating Malachite egg

    One of the most interesting and obvious chemical experiments is the experiment on the interaction of copper sulfate and calcium carbonate. The latter is contained in the shell of a simple egg, but copper sulphate should be searched in a chemical reagent store. This experience is simple, but...

  • Why do copper products change color, and what is the name of the process?

    Probably, every person wants to know, why over time the copper turns green and becomes bloomed. This is easy to explain: that film is called patina.

  • 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...

  • Chemistry of the sky

    Chemistry can teach us about the composition of celestial bodies and determine their age.

  • 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.

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Nuclide Symbol

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.

Nitric Acid

HNO3: A strong acid, it is toxic and can cause severe burns. Transparent colorless or yellowish, fuming, suffocating, caustic and corrosive liquid. Nitric acid boiling point is 83C. A 70 percent solution is used in the S.S.E. laboratory for junction depth measurements. Nitric acid is also present in the metal etch solution used for the Aluminum etch procedure.


Refers to the separation of charge between two covalently bonded atoms.

Double Bond

Covalent bond resulting from the sharing of four electrons (two pairs) between two atoms.

Ionization Constant

Equilibrium constant for the ionization of a weak electrolyte.

Greenhouse Effect

Trapping of heat at the surface of the earth by carbon dioxide and water vapour in the atmosphere.

Molecular Orbital Theory

A theory of chemical bonding based upon the postulated existence of molecular orbitals.


Consisting of only one element.

Ostwald Process

A process for the industrial production of nitrogen oxide and nitric acid from ammonia and oxygen.

Water Equivalent

The amount of water that would absorb the same amount of heat as the calorimeter per degree temperature increase.