previous concepts

previous concepts

1. what is a molecule

   • A molecule is the smallest unit of a chemical compound, consisting of two or more atoms held together by chemical bonds.
     • Quantum numbers: These are numbers associated with physical magnitudes conserved in certain quantum systems. In many systems, the state of the system can be represented by a set of numbers, the quantum numbers, that correspond to possible observable values which commute with the Hamiltonian of the system.
       • Friedrich Hund: Friedrich Hund (February 4, 1896 – March 31, 1997) was a physicist known for his work on the structure of atoms and molecules. Hund's rule is a fundamental principle that has allowed enormous advances in the world of quantum physics and also chemistry
       • Pauli exclusion and energy level: Quantum physics, a fascinating branch of physics that describes the behavior of subatomic particles, has given us numerous fundamental principles that govern the microscopic world. Among these principles, the "Pauli Exclusion Principle" stands out, proposed by the Austro-Hungarian physicist Wolfgang Pauli in 1925. This principle is essential for understanding the structure of atoms and plays a crucial role in the formation of the periodic table of the elements.
   • a molecule is made up of atoms
     • the atoms are
       • is the smallest quantity of a chemical element that has its own existence and is considered indivisible. The atom is made up of a nucleus with protons and neutrons and several orbital electrons, the number of which varies depending on the chemical element.
       • atoms are made up of electrons
         • is a subatomic and elementary particle that orbits around the atomic nucleus. This particle is located in orbitals and is positioned at different energy levels depending on the energy it has.
       • : is one of the particles that is part of the atom. It is a nucleon, since it is found in the atomic nucleus along with protons. It has no electrical charge, and its approximate mass is 1.6749 x 10−27 kilograms. Neutrons are made up of three elementary particles, called quarks.

2. bond: A chemical bond is the force that holds the atoms of a compound together. The force that unites atoms is electromagnetic, and when united, atoms retain their own nature.

3. lewis: A Lewis structure is a structural representation of a molecule in which dots are used to show the positions of electrons around atoms and lines or pairs of dots represent covalent bonds between atoms.

4. Proust: In chemistry, the Law of Constant Proportions, or Law of Definite Proportions, maintains that a chemical compound is always formed by the same proportion by mass of its constituent elements regardless of the method of preparation or source of obtaining.

   • Radiation: is the emission or transmission of energy in the form of waves or particles through space or a material medium.

5. octet: The tendency of atoms, except hydrogen, to have eight electrons in their valence shell.

6. octet: The tendency of atoms, except hydrogen, to have eight electrons in their valence shell.

7. Photon: It is defined as a fraction of light that is scattered in a vacuum. It is a basic particle that is responsible for the quantum samples of the electromagnetic phenomenon, through it all forms of electromagnetic radiation are conducted, not only light, but also X-rays, gamma rays, infrared light, ultraviolet light .

8. Wavelength: It is known as the distance traveled by a periodic disturbance that propagates through a medium in one cycle.

9. work function or removal work, is the minimum energy (usually measured in electron volts) necessary to remove an electron from a solid to a point immediately outside the surface of the solid (or the energy necessary to move an electron from the level of Fermi energy to vacuum).

10. The Compton effect (or Compton dispersion) consists of the increase in the wavelength of a photon when it collides with a free electron and loses part of its energy.

    • valence: In chemistry, we speak of valence to refer to the number of electrons that an atom of a given chemical element has in its final energy level.