An electric heater is an electrical device that converts electric current to heat. The heating element inside every electric heater is an electrical resistor, and works on the principle of Joule heating: an electric current passing through a resistor will convert that electrical energy into heat energy.he direct electric heat exchangers (DEHE) uses heating elements inserted into the shell side medium directly to provide the heating effect. Virtually all of the electric heat generated by the electric circulation heater is transferred into the medium, thus an electric heater is nearly 100 percent efficient.
An atom is the smallest constituent unit of ordinary matter that has the properties of a chemical element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are very small; typical sizes are around 100 picometers (a ten-billionth of a meter, in the short scale).
General Chemistry/Atoms and Molecules - Atoms. 1  An atom is the smallest unit of matter that has the properties of an element. It is composed of a dense core called the nucleus and a series of outer shells occupied by orbiting electrons. 2  The nucleus, composed of protons and neutrons, is at the center of an atom.