Electricity results from the existence of a charge and the interaction of charges. The electric charge in a current is carried by minute particles called electrons (that orbit the nuclei of atoms). Each electron carries a small electric charge. When a stream of electrons moves from atom to atom�for example, inside a copper wire�the flow of the charge they carry is called electric current. Batteries and generators are devices that produce electric current to power lights and other appliances. Electric currents also occur in nature�lightning is a dramatic example.
When a charge is stationary or static, it produces forces on an object in regions where it is present, and when it is in motion, it produces magnetic effects. Electric and magnetic effects are caused by relative position and movement of positively and negatively charged particles of matter. These particles are either positive, neutral, or negative. Protons are positively charged, neutrons are neutrally charged, and electrons are negatively charges. Like charges repeal and unlike charges attract. That is protons attract electrons. |