أكاديميا - كولنز - معاجم الجيب العلمية - الكيمياء - انكليزي - فرنسي - عربي الحرف ٢_ b

Academia - Collins - Pocket Scientific Dictionaries - Chemistry
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bauxite
bauxite m

Bauxite. The main ore from which aluminum is extracted. It is a hydrated oxide (Al2O3.×H20) found in tropical regions, such as northern Australia and western Africa.


beehive shelf
it comes to gas

Bee hive shelf. This device is used to allow gas to be collected above the water level.

A bowl containing water
Gas
Supply pipe
Gas
Bee hive rack
water


benzene
benzène m

petrol . Benzene (CH) is the simplest aromatic compound and is a toxic hydrocarbon that causes cancer. Its widespread use in schools has been replaced by the use of methyl benzene.


beta particles
Particulars fpl beta

Beta particles. Electrons are generated by the following nuclear reaction:

1/o n > 1/1 p + 0/-1 e

Electron, proton, neutron

like :

31/15 p + 1/o n > 32/ 15 p + 0/1 e

In this radioactive decay, electrons are expelled from the nucleus of the atom, traveling very quickly (up to 98 percent of the speed of light) and their ability to penetrate is greater than that of alpha particles. When this reaction occurs, the atomic number of certain atoms changes because they gain protons.


bitumen
bitume m

Red. A mixture of high-boiling hydrocarbons left over from petroleum refining, and used to cover roofs and roads.


blast furnace
haut-fourneau m

High oven. A furnace that enables continuous production of molten iron. The coke reacts at the bottom of the furnace with the hot air:

C (solid) + 02 (gas) → CO2 (gas)

This exothermic reaction raises the temperature to 1800 C, and the coke reacts with carbon dioxide:

C(solid) + CO2(gas) → 2CO(gas)
The carbon monoxide formed raises the iron oxides to iron (1200°C). For example:

Fe2O3 + 3CO → 3CO2 + 2Fe
(liquid) (gas) (gas) (solid)

The molten iron flows to the bottom of the furnace. The limestone in the oven decomposes due to heat, turning into calcium oxide and carbon dioxide. Calcium oxide reacts with iron metal impurities - silica (SiO2) - to form molten slag:

(liquid)
Cao (solid) + SiO2 (solid) →CaSiO3

This output falls to the bottom of the furnace, where it floats on the surface of the iron. The iron produced in the furnace contains about 3 percent carbon, and the metal is brittle. The percentage of impurities is carefully controlled when making steel. See drawing.

Iron fuel (limestone, metal, coke)

Waste gas (N2 + CO) is burned to heat the incoming air.

Limestone, coke and iron ore
Lining of steel and brick
hot air
Molten iron
malice
High oven