It comes to your house through electrical wires. The wire is not like an empty garden hose that water flows through. You'll remember in Chapter 1 that energy can be conducted. Heat energy was conducted from the heat through the soup pan to the soup. All matter is made up of atoms, and atoms are made up of smaller particles, one of which is the electron.
Electrons spin around the center, or nucleus, of atoms, just like the moon around the earth.
The nucleus is made up of neutrons and protons. Electrons have a charge, a negative charge. Protons have a positive charge and neutrons are neutral or have neither a positive nor a negative charge. Some kinds of atoms have electrons that are loosely attached. They can easily be made to move from one atom to another.