Electricity and magnetism

• Atoms are made from nuetrons, electron, and protons.
• Protons are positively charged. Electrons are negatively charged. Neutrons are neutral.
• The force between charged particles or objects is called electric force.
• An electric charge has an invisible electric field around it— a region around the charged particle or object where the electric force is exerted on other charged particles or objects.
• The continuous flow of charge is know. As electric current. The current is measured as a rate in units called amperes.
• This difference in electric potential energy per change is called voltage. The voltage acts like a force that causes a current to flow. Voltage is measured in volts (V).
• Some materials have electrons that are tightly bound to their atoms. Electrons are difficult to move. They are called insulator.
• Loosely bound electrons are conductors, they allow charge to flow more freely.
• When charges build up on an object, they do not flow like current. Instead, they remain static, meaning they stay in place. This buildup of charge on an objects is called static electricit.
• objects can become charged by four methods: conduction, friction, induction, and polarization.
• Conduction is the movement of charge by direct contact between objects.
• Friction occurs when two objects rub against each other and electrons move from on object to the other.
• Induction can be caused without even touching. The electric field of one charged object repels the electrons of the other objects. The second object has a buildup of charge on its opposite side.
• Polarization is when the electrons only move to the opposite side of their atoms rather that to the opposite side of the entire object.
• Most objects that become charged eventually lose their charge to the air. Charge transfers to or from the air until the charged object is neutral.
• A magnet attracts iron and materials that contain iron.
• Magnets attract iron and some other material— usually metals. They attract or repel other magnet. This attraction or repulsion is called magnetism.
• Magnetism is caused by a force that can act at a distance. This magnetic force is a push or pull that occurs when a magnet interacts with another object.
• Every magnet has two ends, called magnetic poles. Where the magnetic force is strongest.
• As you apply force to separate the two opposite poles, the potential energy if the system increase.
• There us an area of magnetic force that surrounds a magnet. This area of force is the magnetic field of the magnet. This allows magnets to attract objects at a distance.