Skip to content

Category «General terms»

Material point

Матеріальна точка

A material point is a physical model of an object, in which its dimensions and mass can be neglected for the purposes of a given problem. However, the object retains other physical characteristics, such as velocity, acceleration, momentum, and energy.

History of iron

History of iron

Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal with a silvery-gray appearance and a density of 7.87 grams per cubic centimeter. It is the fourth most abundant element in the Earth’s crust and one of the most useful metals in human history. Iron has been used …



Radioactivity (from Latin: radio – “emit” and activus – “active”) is the property of certain elements and isotopes that have unstable atomic nuclei and can emit excess energy in the form of particles or electromagnetic radiation.



Isotope – is a variety of an atom of a chemical element that differs from other isotopes of the same element in the number of neutrons in the nucleus. In other words, all atoms of one element have the same number of protons in the nucleus (which determines its atomic number) but can have different …



Neutron – is an elementary particle with no electric charge that is part of the atomic nucleus. History of Neutron Discovery The discovery of the neutron was a significant event in the history of science. Before that time, two main particles of the atom were known: electrons, which have a negative charge and move around …



Proton – is an elementary particle that constitutes the nucleus of an atom along with neutrons. It has a positive electric charge and is symbolized by the letter “p.”


Electron (Greek Ηλεκτρόνιο) is an elementary particle carrying a negative electric charge. It is one of the fundamental constituents of atoms, alongside protons and neutrons.



The atom is the basic unit of matter, consisting of a nucleus of protons and neutrons, surrounded by electrons that orbit the nucleus in shells or energy levels.



Superconductor is a material that at very low temperatures (close to absolute zero) has zero electrical resistance and allows electric current to flow without any energy loss. The most well-known superconductor is mercury, which has zero resistance at a temperature of 4.2 K (-268.8 °C). However, due to the instability and toxicity of mercury, its …