atomic and molecular structure of matter has been actively studied by Lomonosov.Russian scientist first used in chemistry theory, the essence of which was to a certain position.
- All substances included in its membership, "corpuscles."This term is called the Lomonosov molecule.
- corpuscles are composed of "elements".This term is used to refer to Lomonosov atoms.
- all particles (atoms and molecules) are continuously moving.Thermal state of all bodies is the result of motion of the constituent particles.
- identical atoms make up molecules of simple substances, different atoms - molecules in complex substances.
atomistic doctrine applied subsequently Dalton.The basis of the theory of the English scientist, describing the structure of matter, repeating the theory of Lomonosov.However, Dalton more developed it.English scientist was trying to determine the atomic weight of elements known at that time.This Dalton denied that the molecules of simple substances, arguing that the simple substance contains only atoms.While complex elements include "complex atoms."
finally adopted the doctrine of atomic and molecular structure of matter only to the mid-19th century.
molecule is called the smallest particles of matter.It has all the chemical properties of the element.Atoms - the smallest particle included in the molecular complex and simple substances.The composition of the atom determines the chemical properties of elements.Under this provision, should be the modern definition of the smallest particles.Thus atom is electrically neutral particle.It consists of a nucleus, positively charged, and electrons, negatively charged.
In accordance with modern concepts, molecules are vaporous and gaseous bodies.In solids, the smallest particles (molecules) are present provided that the crystal lattice, which, in turn, has a molecular structure.
There are several major provisions of the teachings.
theory to explain the structure of matter, indicates the presence of certain gaps between the particles.The size of these distances depend on the temperature and state of aggregation of the object.The greatest gaps occur between the molecules in the gaseous bodies.This leads to the ability of gas is easily compressed.Significantly shorter the distance between the molecules in the liquid, so they are compressed harder.Solids are resistant to compression, due to the fact that the gaps between the particles are small.
molecules are constantly in motion.The above body temperature, the higher the speed.Between the particles there are the forces of mutual attraction and repulsion.
molecules contain atoms which also are in continuous movement.
One kind of atoms is different from the other in properties and weight.Substances
molecular structure in the solid state components are crystalline lattices that include molecules.Links between particles are weak and burst when heated.Thus, such bodies possess low melting points.
Body may have another structure.The substances can consist of atoms and other particles, which constitute the nodes of the crystal lattices (e.g., iron, other metals).Between these particles, there are very strong ties.To destroy them, you need to spend a lot of energy.Such a structure of matter involves a high melting point.
On the basis of the doctrine explains many phenomena.For example, diffusion.This process is based on the ability of the particles, molecules, atoms penetrate into the interspaces present between the atoms or molecules of a different material.This, in turn, is possible due to the constant motion of particles that make up the body.