Спереводом текста без онлайн переводчика! the nature of electricity practical electricity is produced by small atomic particles known as electrons. it is the movement of these particles which produce the effects of heat and light. accepted atomic theory states that all matter is electrical in structure. any object is largely composed of a combination of positive and negative particles of electricity. electric current will pass through a wire, a body, or along a stream of water. it can be established in some substances more readily than in others, that all matter is composed of electric particles despite some basic differences in materials. the science of electricity then must begin with a study of the structure of matter. matter is defined as any substance which has mass (or weight) and occupies space. this definition should be broad enough to cover all physical objects in the universe. wood, water, iron, and paper are some examples of matter. energy is closely related to, but not to be confused with, matter. energy does not have mass, and it does not occupy space. heat and light are examples of energy. the smallest particle of matter which can be recognized as an original substance was thought to be a unit called the atom. recently scientists have found particles even smaller than atoms, but our theories are still based on the atom. the atom consists of a nucleus and a cloud of electrons. it is generally agreed that the electrons are small particles of electricity, which are negative in nature. these particles orbit the nucleus in much the same fashion that planets orbit a sun.