أكاديميا - كولنز - معاجم الجيب العلمية - الفيزياء - انكليزي - فرنسي - عربي الحرف ٦_ p

Academia - Collins - Pocket Scientific Dictionaries - Physics - English - French - Arabic Letter 6_ P


proton
proton m

proton. One of the three main particles that make up matter. The proton has a single positive charge on the nuclear scale and its mass is equal to one atomic mass unit.
See nucleon number.

The nucleus of any atom contains one or more protons. The actual number is the number of protons, proton number Z. The number of electrons is equal to Z in the neutral atom.


proton number (Z)
number m protonique

Number of protons. It is the number of protons in the nucleus of an atom. If the number of protons is added to the number of neutrons, N, the sum gives us A, i.e. the nucleon number. People used to call Z the atomic number. All of these measurements are numbers without a unit. We can describe any atom using it. Their values ​​allow us to predict chemical and physical properties. When writing about atoms, nuclei, and the interactions between them, we use symbols consisting of three sections. The figure below represents the nuclide carbon-14, one of the isotopes of carbon.

N = A - Z Number of neutrons
Number of newbies A
The number of protons Z


pulley
poulie f

early. A class of machines in which energy is transmitted from input to output by means of tension in a rope, chain, or cable. One or more pulleys change the direction and/or magnitude of the applied force. We usually tend to ignore friction in the pulley holders and any stretching of the rope. We often assume the return is equal to one hundred percent.

Speed ​​ratio = 4
Speed ​​ratio = 2
Speed ​​ratio = 1


pump
pompe f

Pump. A device for moving a fluid, usually against gravity. The lift pump, (a) below, can lift water 10 metres. The force pump pushes the water to higher heights (B). Car tire pumps (inflators) are similar to the latter.


pumped storage system
stockage m entretenu

Pumped storage system. See hydroelectricity.