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

Latest Articles

  • Ozone

    We breathe 24 hours a day, 7 days a week, consuming about 25 kg of air every day. It turns out that we practically predetermine our health by the air we breathe.

  • Interesting facts about metals

    Metals have been used by people since ancient times. All the time the process of obtaining them was improved, useful alloys of various metals appeared. Let’s look at interesting facts about metals.

  • 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...

  • 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...

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Law of Conservation of Matter

There is no detectable change in the quantity of matter during an ordinary chemical reaction.

Intermolecular Forces

Forces between individual particles (atoms, molecules, ions) of a substance.

Band Theory of Metals

Theory that accounts for the bonding and properties of metallic solids.

Gem-dimethyl group

Two methyl groups of the same carbon atom.

Particulate Matter

Fine divided solid particles suspended in polluted air.

Nuclear Fission

The process in which a heavy nucleus splits into nuclei of intermediate masses and one or more protons are emitted.

Electron Configuration

Specific distribution of electrons in atomic orbitals of atoms or ions.

Chemistry of the sky

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


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.