What Is a Proton?

A proton is a subatomic particle with a positive charge of 1.6 × 10 ^-19 Coulomb (C), a diameter of about 1.6 ~ 1.7 × 10 ¹⁵ m and a mass of 938 million electron volts / c² (MeV / c²) That is 1.726621637 (83) × 10 ^-27 kg, which is approximately 1836.5 times the mass of the electron (the mass of the electron is 9.10938215 (45) × 10-31 kg), and the proton is slightly lighter than the neutron (the mass of the neutron is 1.674927211 (84) × 10 ^-27 kg). Protons belong to the baryon class and are composed of two upper quarks and one lower quark through gluons under strong interaction. The number of protons in the nucleus determines its chemical properties and which chemical element it belongs to.

Relative mass 1.007

Charge +1 yuan charge (+ 1.60217733 × 10 ^-19

In 1919, Rutherford conducted an experiment of bombarding nitrogen nuclei with alpha particles. The experimental device is shown in the figure. The container C contains radioactive material A. The alpha particles emitted from A are shot on the aluminum foil F. The thickness of the aluminum foil is appropriately selected. After the container C is evacuated, the alpha particles are just absorbed by F and cannot be transmitted. A fluorescent screen S is placed behind F, and a microscope book is used to observe whether a flash appears on the fluorescent screen. After introducing nitrogen into C through valve T, Rutherford observed a flash from phosphor screen S, and replaced the nitrogen with oxygen or carbon dioxide, but no flash was observed, which indicates that the flash must have been generated by alpha particles hitting the nitrogen nucleus. New particles caused by permeation of aluminum foil.

Rutherford introduced this kind of particle into the electric and magnetic fields. According to its deflection in the electric and magnetic fields, measured its mass and electric quantity, and determined that it is a hydrogen atomic nucleus, also known as a proton. Usually, the symbol Rutherford puts this This kind of particle is introduced into the electric and magnetic fields. According to its deflection in the electric and magnetic fields, its mass and electric quantity are measured, and it is determined that it is a hydrogen atomic nucleus, also called a proton, which is usually represented by a symbol.

Is the proton emitted directly from the nitrogen nucleus, or is it released when the re-nucleation formed by the alpha particles entering the re-nucleation decays? In order to understand this problem, the British physicist Brackett was again in a nitrogen-filled cloud chamber This experiment was done here. If the protons are ejected directly from the nitrogen nucleus, then four tracks will be seen in the cloud chamber: the tracks of the radiating alpha particles and the scattering after collision. The tracks of particles, the tracks of protons, and the recoil tracks of the nucleus after protons are thrown. If a particle enters the nitrogen nucleus and forms a re-nucleus, this re-nucleation decays immediately and releases a proton, then three tracks can be seen in the cloud chamber: the track of the incident alpha particle, the track of the proton, and the track of the recoil nucleus trace. Brackett took more than 20,000 photos of the cloud chamber, and finally found that from more than 400,000 "particle trails", eight had forks. The situation of the fork shows that this second assumption is correct From the conservation of mass and charge, it can be known that the new nucleus produced is oxygen 17.

In the photo of the cloud chamber, the traces of the protons after the bifurcation are thin and long, and the traces of the recoil oxygen nuclei are short and thick.

Later, people used similar methods to make similar changes in the cores of fluorine, sodium, and aluminum, and all produced protons. Since protons can be bombarded in various nuclei, it can be seen that protons are part of the nucleus.

Protons are often used in physics

Protons have so far been considered a stable,

Antiproton

Under great pressure, the super-solid matter makes the nucleus and electrons that were already tightly crowded tighter. At this time, the nucleus is forced to dissolve and release protons and neutrons from it. Protons released from the nucleus will combine with electrons to form neutrons under extreme pressure. In this way, the structure of matter has undergone a fundamental change. Materials that were originally constructed from atomic nuclei and electrons have now become neutrons. This state is called "

Acid-base

Proton conservation means that the number of protons lost by the acid and the base is the same. The conservation of protons is the same as that of materials. The conservation of charge is the same as the three major conservation relationships in solution. The conservation of protons can also be obtained from the relationship between the conservation of charge and the conservation of materials. In solution, the following equation exists C (H ⁺ ) + C (Na ⁺ ) = C (HCO _3- ) + 2C (CO ₃ ^2- ) + C (OH-) This formula is called charge conservation C (Na ⁺ ) = C (HCO _3- ) + C (CO ₃ ^2- ) + C (H ₂ CO ₃ ) This formula is called material conservation

Method 1: Subtract two formulas to get C (H ⁺ ) + C (H ₂ CO ₃ ) = C (CO ₃ ^2- ) + C (OH-). This formula is called proton conservation. Method 2: The original species from the theory of acid-base protons: HCO _3- , H ₂ O consumes the proton product H ₂ CO ₃ to produce the proton product CO ₃ ^2- , OH-C (H ⁺ ) = C (CO ₃ ^2- ) + C (OH-) -C (H ₂ CO ₃ ) is C (H ⁺ ) + C (H ₂ CO ₃ ) = C (CO ₃ ^2- ) + C (OH-) Relationship: The number of remaining protons is equal to the number of protons The number of products-the number of products that consume protons. It is relatively simple to use the acid-base proton theory to find the proton equilibrium relationship, but you need to be careful; if you use the charge conservation and the material conservation relationship to get it together, it is more troublesome, but it is more secure, such as NaH ₂ PO. ₄ solution, original species: H ₂ PO _4- , H ₂ O, proton-consuming products: H ₃ PO ₄ , proton products: HPO ₄ ^2- (produce one proton), PO ₄ ^3- (produce two protons), OH-, so: c (H ⁺ ) = c (HPO ₄ ^2- ) + 2c (PO ₄ ^3- ) + c (OH-)-c (H ₃ PO ₄ ) can be verified simultaneously with charge conservation and material conservation under.