أكاديميا - كولنز - معاجم الجيب العلمية - الكيمياء - انكليزي - فرنسي - عربي الحرف ٣_ r

Academia - Collins - Pocket Scientific Dictionaries - Chemistry - English - French - Arabic Letter 3_ R


relative molecular mass (R.M.M.)
Masse relative moléculaire

Relative molecular mass. See Mr.


residue
résidu m

remains. residual. What remains after the end of any chemical process. It is also called the remaining material in a filter paper.


respiration
respiration f

Breathing. The process by which plants and animals obtain energy.

Animals eat food that breaks down in the body. Oxygen is taken in when air is inhaled and enters the lungs. Blood transports oxygen to all parts of the body. Reactions take place between oxygen and the broken down food and heat is released. It also produces carbon dioxide, which is exhaled. The remaining food waste is excreted out of the body. The body uses absolute energy to obtain heat, movement, growth, and all other functions.

food
Breathing
food
oxygen
Chemical reactions in the body
Energy + waste


reversible reactions
Reactions are available

Reversible reactions. A reversible reaction is a reaction that can
It happens in both directions according to existing conditions.

Fe2O3 + 3H2= 2Fe + 3H2O
(gas) (solid) (gas) (solid)

The steam can react with the hot iron or the hydrogen can return iron(III) oxide. In both cases, equilibrium is achieved with the presence of all four substances if the resulting substances are not removed.


rock salt
Sell ​​me gemme

Rock salt. Impure crystalline precipitates of sodium chloride are known by this name. The solid material is purified before use.


room temperature
ambient temperature

Normal temperature. Temperature ranges between 15° and 25° C. It is not a specific temperature, but rather a range of temperatures.

rubber
caoutchouc m

A natural polymer and hydrocarbon bonded rubber with the following structure:
C=C
C=C

Most of the rubber used today is man-made.
It is made from butadiene:

(CH2=CH-CH=CH2)

By polymerization. Rubber is flexible and a good insulator, and has a wide range of uses, ranging from car tires, gloves, and waterproofing. . . Etc.


rust
rouille f

Rust. The reddish-brown result of corrosion of iron exposed to air and water. It is hydrated iron (III) oxide (Fe2O3 × H2O). Rust is of great economic importance and is usually avoided by coating iron with paint or covering it with plastic or another metal.
See electroplating and galvanizing.