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A device used to measure the heat transfer between system and surroundings at constant volume.

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  • 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.

  • 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...

  • Diamonds Are Forever

    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?

  • 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.



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Nonpolar Bond

Covalent bond in which electron density is symmetrically distributed.

Covalent Bond

Chemical bond formed by the sharing of one or more electron pairs between two atoms.

Background Radiation

Ratiation extraneous to an experiment. Usually the low-level natural radiation form cosmic rays and trace radioactive substances present in our environment.

Standard Molar Enthalphy of Formation

The amount of heat absorbed in the formation of one mole of a substance in a specified state from its elements in their standard states.

Electrolyte

A substance whose aqueous solutions conduct electricity.

 

Hydride

A binary compound of hydrogen.

 

Zinc

Discovered: known in India and China before 1500 and to the Greeks and Romans before 20 BC as the copper-zinc alloy brass
Origin: The name is derived from the German ‘Zink’.
Atomic no: 30
Mass No: 65
Description: A grey metal with a blue tinge. World production exceeds 7 million tons a year, and it is used to galvanise iron to prevent it rusting. It is also employed in alloys and batteries, and as zinc oxide to stabilise rubber and plastics. Zinc is essential for all living things, and is important for growth and development. The average human body contains about 2.5 grams and takes in about 15 milligrams per day. Some foods have above average levels of zinc, including herring, beef, lamb, sunflower seeds and cheese.

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 effective and visual, and as a result we will get something beautiful.

Dosimeter

A small, calibrated electroscope worn by laboratory personnel and designated to detect and measure incident ionizing radiation or chemical exposure.

Critical Point

The combination of critical temperature and critical pressure of a substance.