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).
Molecules. A molecule is two or more atoms bonded together chemically. An atom is the most basic unit of matter. When atoms are chemically bonded together with covalent bonds, molecules are formed. Molecules can be very small like water molecules or extremely large like proteins such as hemoglobin. Upon examination of a chemical formula for a molecule we see the element symbols marked with a subscripted number. The number represents the amount of that atom present within the molecule. If we are looking at water which has a chemical formula of H 2 O, this refers to 2 atoms of hydrogen bonded to one atom of oxygen.