أكاديميا - كولنز - معاجم الجيب العلمية - الكيمياء - انكليزي - فرنسي - عربي الحرف ١_ m

Academia - Collins - Pocket Scientific Dictionaries - Chemistry - English - French - Arabic Letter 1_ M


M
See molarity.

Mr

Symbol for the relative molecular mass of a compound or molecule. It can be calculated by summing the relative atomic masses of each atom in the molecule.

Example :

Mr = 12 + 16 = 28
for carbon monoxide

Mr = (1 x 2) +16 = 18
Waterproof


macromolecule
macromolecule f

Macromolecule. This term means a large molecule.
It is usually used to describe molecules whose relative molecular masses exceed one thousand, that is, polymers such as carbohydrates and types of plastics such as polyethene, as well as molecules such as proteins and nucleic acids.


magnesium
magnesium m

Magnesium is a shiny, gray metal from Group II. It is well reactive and reacts strongly with acids. It burns intensely in the air, giving off a bright white light, which is why it is used in torches, fireworks, and photographic lighting lamps. It also burns in carbon dioxide and reacts with steam to produce hydrogen. The metal is obtained by electrolysis of molten magnesium chloride, most of which is extracted from water
the sea .

Magnesium is mainly used in the production of low-density alloys used in the aircraft industry.


magnesium compounds
Compositions of magnésium

Magnesium compounds.

Magnesium hydroxide Mg(OH)2

It is obtained by treating seawater with calcium hydroxide, and is used in pharmaceutical products such as milk of magnesia as a treatment for increasing stomach acidity.

Magnesium carbonate MgCO3

This compound is found naturally as magnesite and dolomite (MgCO CaCO3) and is used in making heat-resistant materials.

Magnesium oxide MgO

This important heat-resistant compound is made
By heating carbonates.

Magnesium chloride MgCl2

After extracting this compound from seawater, it is melted and electrolyzed to produce magnesium metal.

Magnesium sulphate MgsO4

Epsom salts or Epsomite. These crystals are used to treat constipation. It is also used as a fire retardant agent.


malleable
malleable

Compliant. The malleable material can be hammered and shaped into different shapes. The larger the crystals of the material, the greater its ductility. The ductile material is also ductile. Metals and alloys have these two characteristics.


maltose (C12H22O11)
maltose m

Maltose is a disaccharide molecule, resulting from the breakdown of starch, and maltose is a glucose dimer.


manganese
Manganèse m

Manganese Manganese is a transition metal that occurs naturally in the form of oxide (MnO2) and is extracted either by electrolysis of sulfate or by the ther mit reaction. This metal is mainly used in alloys such as steel and bronze.


manganese compounds
Compositions of manganese

Manganese compounds. Manganese forms compounds in which the metal valences are 2, 3, 4, 6, and 7, and the most important valences are 2, 4, and 7.

Manganese (IV) oxide MnO2

This compound has an important use in batteries
Dry, it is used as a catalyst and an oxidation agent.

Potassium manganate (VII) KMnO4

A bright purple crystalline substance that forms a powerful oxidizing agent, used as an anti-mold, and produces the MnO-4 ion.