1.1 field lines

• negatively charged: having more electrons than protons, creating an imbalance
• positively charged: having fewer electrons than protons, creating an imbalence
• coulomb: an SI unit for charge; one coulomb is equivalent to the transfer of 6.25x10^18 electrons
• conductor: a material in which some of the electrons can move freely, allowing the material to conducts an electric current
• electric potential energy difference: the change in potential energy per unit of charge
• volt: the unit for electric potential difference; 1 V = 1 J/C
• voltage: the change in electrical potential energy per unit of change (J/C)
• electric field: a property of the space around a source charge that enables the source charge to exert forces on other charges that enter this region
• insulator: a material in which none of the electrons can move freely, preventing the material from being able to conduct an electric current
• test body: an observable object that can experience a force due to the presence of a feild
• magnetic field: a property of the space around a magnet or an electric current that enables the magnet or electric current to exert forces on other magnets such as compass needles
• gravitational field: a property of the space around a source mass that enable the source mass to exert forces on other masses that enter this region
• field lines: lines that describe the direction of a field by the way they point, and the strength of a field by density