of the Atom

By 1911, the atomic composition was discovered. The atom consists of subatomic particles called protons and electrons. However, it is not clear how these protons and electrons are arranged in atoms. Thomson proposed a "plum pudding" mode. In this model, electrons and protons are uniformly mixed throughout the atom.

Rutherford examined Thomson's hypothesis by planning his "gilt" experiment. Rutherford believes that if Thomson's model is correct, the mass of atoms will spread throughout the atom. Then, if he shoots fast alpha particles (nucleus) on one atom, there is little alpha particle deflection. He decided to test it with a thin layer of gold atoms. As expected, most alpha particles only pass through the gilt, but surprisingly, some alpha particles almost bounce directly.

These deviations are incompatible with Thomson's model. Rutherford was forced to abandon the plum pudding model and concluded that the only way to deflect alpha particles backward is when most of the mass in the atom is concentrated in the nucleus. Therefore, he developed a planet model of atoms. And it put all the protons at the nucleus, and the electrons orbits the planet around the nucleus like a planet turning around the sun.

Rutherford atomic model, also known as atomic or atomic planetary model, was described by the atomic structure of New Zealand - born physicist Ernest Rutherford (1911). In this model, atoms are described as small, dense, positively charged cores called nuclei. Almost all the masses are concentrated in it. Like a planet turning around the sun. Like a series of experiments conducted by undergraduate Ernest Mazden in 1909 under the guidance of Rutherford and German physicist Hans Geiger, the nucleus was small to explain the scattering of alpha particles in thin gold leaf Please assume it is dense. As observed. This source can emit alpha particles (ie particles with the same mass as the ruthenium nucleus and positively charged 7000 times larger than electrons) and are enclosed in protective lead shields.

Alpha radiation (α) is the emission of alpha particles from the nucleus. The alpha particle contains two protons and two neutrons (and is similar to the He nucleus :). When an atom releases a particle, the atomic weight of the atom decreases by 4 units (since two protons and two neutrons are lost), the atomic number (z) decreases by 2 units. This element is called a "transition" to another smaller z-element. As shown in the following equation, the alpha enthalpy example occurs when uranium collapses into element enthalpy (Th) by releasing alpha particles.

An atom is defined by the number of protons and neutrons. The number of protons represents the number of atoms and determines which element is an atom. Neutron contributes to atomic stability and determines the number of isotopes. The most important stabilizing element found by humans is lead, and there is sufficient evidence that there are 82 protons. Due to the structural symmetry of the atoms, some isotopes of lead with different numbers of neutrons are stable for their "mysterious" number of protons. Normally, atoms with many protons and neutrons become asymmetric in atomic structure, become unstable and collapse into lighter elements. However, chemists have speculated that some of these very heavy elements may have stable isotopes