The atom is a structure in which matter is organized in the physical world or in nature. The atoms form the molecules, while the atoms in turn are formed by subatomic constituents such as protons (with positive charge), neutrons (without charge) and electrons. (with negative charge).
In a graphical way, what is an atom? Let's imagine that we have a piece of iron. We split it. We still have two pieces of iron but smaller ones. We will start them again, again ... Each time we will have more smaller pieces until a moment will come, in which if we go back to…
In physics and chemistry, the atomic theory is a scientific theory of the nature of matter, which states that matter is composed of units called atoms. Atomic theory began as a philosophical concept in ancient Greece and entered the mainstream of the nineteenth century when discoveries in the field of chemistry showed that matter really behaves as if it were an atom.
The word atom originates in the atomic adjective of the ancient Greek, which means "indivisible". As explained in the history of nuclear energy. Nineteenth-century chemists began to use the term in relation to the growing…
A molecule is a set of chemically bonded atoms. The electric charge of the molecules is neutral.
There is a definition of an older molecule that is less general and less precise: "A molecule is the smallest part of a substance that can have an independent and stable existence while preserving its chemical properties and certain physicochemical properties." By this definition there could be molecules with a single atom. Types of molecules
Molecules can be formed in two different ways:
- Discrete molecules: molecules may consist of a well-defined number of atoms…
Atomic energy comes from the atom, it is the energy that holds together neutrons and protons of the nuclei of atoms. It is also known how nuclear energy, which comes from the nucleus. The name nuclear energy is used because most of the energy of an atom resides in its nucleus.
Two parts of the atom, the nucleus and the crust are differentiated. In the cortex, an indeterminate number of electrons orbit around the nucleus. The nucleus is composed of an indeterminate number of neutrons and protons. The amount of protons in the nucleus will determine the element that the atom is treated,…
The moderator is a component that is part of nuclear reactors. It is located in the reactor core. The function of the moderator is to reduce the speed of neutrons in nuclear fission reactions.
During fission nuclear reactions, neutrons collide with fissile atoms (uranium and plutonium) present in the nuclear fuel causing fission. With each fission reaction, one or two neutrons are released at high speed.
The objective to maintain a chain fission reaction is that these neutrons hit other fissile atoms but at such a speed it is very difficult. The objective of…
To explain the history of nuclear energy we could distinguish three major stages:
- Physical and chemical scientific studies of the elements.
- The development of the nuclear bomb during World War II.
- Use of nuclear energy in the civil field.
Scientific studies cover this whole period since the first Greek philosophers began to define atoms, until the development of the first nuclear bomb. In this process, different scientists discover the presence of electrons, neutrons and protons and properties that make one atom more radioactive than another.…
In physics and chemistry, an ion is an atom or molecule that does not have a neutral electrical charge. A cation with a positive electric charge is called a cation, and an ion with a negative electric charge is anion.
The process of winning or losing electrons (with respect to the neutral atom or molecule) is called ionization. Cations and anions are usually represented by the symbol of the corresponding atom and the symbol "+" or "-", respectively. If the number of electrons gained or lost is greater than one, this is also indicated.
The cations and anions are…
Enriched uranium is uranium that has gone through a technological process to increase the proportion of the uranium-235 isotope. As a result, natural uranium is divided into enriched uranium and depleted uranium.
Natural uranium contains three isotopes of uranium: uranium-238 (99.2745%), uranium-235 (0.72%) and uranium-234 (0.0055%). The isotope uranium-238 is a relatively stable isotope, incapable of an independent nuclear chain reaction, unlike the rare uranium-235. Currently, uranium-235 is the main fissile material in the chain reactions of nuclear…
The atomic nucleus is the small central part of the atom, with positive electric charge and in which most of the mass of the atom is concentrated. It was discovered by Ernest Ruthenford in 1911. After the discovery of the neutron, in 1932, the atomic nucleus model was quickly developed by Dmitri Ivanenko and Werner Heisenberg.
The main subatomic particles of the nuclei of atoms are protons and neutrons or nucleons (except that of ordinary or own hydrogen, which contains only one proton). The same chemical element is characterized by the number of protons in the nucleus that…
Isotopes are atoms whose nuclei have the same number of protons but different numbers of neutrons. Not all atoms of the same element are identical and each of these varieties corresponds to a different isotope.
Each isotope of the same element have the same atomic number (Z) but each has a different mass number (A). The atomic number is the number of protons in the atomic nucleus of the atom. The mass number is the sum of neutrons and protons of the core. This means that different isotopes of the same atom differ from each other only by the number of neutrons.
The items that can…
The atomic number is a physical and chemical concept related to the structure of the atoms of each element. The total number of protons (elementary positive charges) of the nucleus of a given atom is treated. It is represented by the letter Z. The conventional symbol Z possibly comes from the German word Z ahl which means number.
The atomic number is used to classify elements within the periodic table of elements.
The sum of the atomic number Z and the number of neutrons N gives the mass number A of an atom. Atoms with the same atomic number Z, but different numbers of neutrons…
What is nuclear energy? Nuclear energy is the internal energy in the atomic nucleus, that is, the central part of an atom. Atoms are the smallest particles in which a material can be divided. The nucleus of an atom is composed of two subparticles: neutrons and protons. These subparticles are held together due to energy links. At the moment in which these bonds are modified, a large amount of thermal energy is released in the form of heat.
Nuclear technology deals with the use of this internal energy for a wide variety of applications. The most well-known…
The basis of everything related to nuclear energy lies in the atom, since nuclear technology is based on the use of the internal energy contained in atoms. For this reason, to understand how nuclear reactions occur (nuclear fission or nuclear fusion) it is useful to understand how an atom is structured.
An atom is the smallest constituent unit of ordinary matter that has the properties of a chemical element.
The atom is composed of a nucleus and one or more electrons linked to the nucleus. The nucleus is made of one or more protons and, typically, a similar number of…
Nowadays, the main use given to nuclear energy is the generation of electric power. Nuclear power plants are responsible of doing this process. Almost all nuclear power plants in production are using nuclear fission since the nuclear fusion, despite being under development, is currently unfeasible.
The operation of a nuclear power plant is identical to the operation of a thermoelectric power plant working with fossil fuels like coal, oil or gas, except in the way of providing heat to the water for converting this one into steam. In nuclear reactors this process of producing heat is made…
A nuclear power plant is a facility for obtaining electrical energy using nuclear energy.
Its operation is similar to that of a thermal power plant or that of a solar thermal plant: from a source of energy thermodynamics is used to obtain heat, with the heat to get steam and with the steam to drive a turbine that will generate electricity.
The difference between the different types of electrical installations is in the energy source: a nuclear power plant uses the heat released in the nuclear fission reactions of certain atoms, in a thermal power station the heat source (thermal…
An electron is a stable negatively charged elementary particle which is one of the fundamental components of the atom. For this reason it can also be defined as a subatomic particle. It is part of the group of leptons.
Electrons may appear in the free state (without being attached to any atom) or attached to the nucleus of an atom. There are electrons in atoms spherical layers of different radious. These spherical layers represent energy levels. The larger spherical shell, the greater the energy contained in the electron.
In the electrical conductors, the current flows results…
Nuclear fusion is a nuclear reaction through which two light nuclei of atoms, usually hydrogen and its isotopes (deuterium and tritium), are combined forming a heavier nucleus. This binding is usually accompanied by the emission of particles (in case of deuterium nuclei one neutron is emitted). This nuclear fusion reaction releases or absorbs a lot of energy in the form of gamma rays and kinetic energy of the emitted particles.This large amount of energy transforms matter to a plasma state.
The nuclear fusion reactions can emit or absorb…