# Unit 4: Physics **SCIENCE — WORD WALL** |Term |Definition| |:----|:---------| |Static Electricity | an imbalance of electric charge on the surface of an object| |Electron | a negatively charged particle in an atom| | Proton | a positively charged particle in the atom’s nucleus| | Electric charge | a form of charge, either positive or negative, that exerts an electric force| | Neutral charge | an object that has equal numbers of protons and electrons| | Negatively charged object | an object that has more electrons than protons| |Positively charged object | an object that has fewer electrons than protons| | Electric force | the force exerted by an object with an electric charge; can be a force of attraction or a force of repulsion| | Induced charge separation | a shift in the position of electrons in a neutral object that occurs when a charged object is brought near it| | Charging by friction | the transfer of electrons between two neutral objects (made from different materials) that occurs when they are rubbed together or come in contact (touch)| | Electrostatic series | a list of materials arranged in order of their tendency to gain electrons| | Charging by conduction | charging an object by contact with a charged object| | Grounding | connecting an object to a large body, like Earth, that is capable of effectively removing an electric charge that the object might have| | Conductor | a material that lets electrons move easily through it| | Insulator | a material that does not easily allow the movement of electrons through it| | Charging by induction | charging a neutral object by bringing another charged object close to, but not touching, the neutral object| | Electric discharge | the rapid transfer of electric charge from one object to another| | Lightning | a bolt of electricity from sky :D| | Current electricity | the controlled flow of electrons through a conductor| | Electric circuit | a continuous path in which electrons can flow| | Switch | a device in an electric circuit that controls the flow of electrons by opening (or closing) the circuit| | Load | the part of an electric circuit that converts electrical energy into other forms of energy| | Electrical energy | the energy provided by the flow of electrons in an electric circuit| | Electric cell | a device that converts chemical energy into electrical energy| | Fuel cell | ?| | Direct current (DC) | a flow of electrons in one direction through an electric circuit| | Alternating current (AC) | a flow of electrons that alternates in direction in an electric circuit| | Electrical power | the rate at which electrical energy is produced or used| | Kilowatt-Hour | the SI unit for measuring electrical energy usage; the use of one kilowatt of power for one hour| | Efficiency | comparison of the energy output of a device with the energy supplied| | Circuit | a way of drawing an electric circuit using standard symbols| | Series circuit | a circuit in which the loads are connected end to end so that there is only one path for the electrons to flow| | Parallel circuit | a circuit in which the loads are connected in branches so that there are two or more paths for electrons to flow| | Potential difference (voltage) | the difference in electrical potential energy per unit charge measured at two different points; measured in volts| | Voltmeter | a device used to measure potential difference (voltage)| | Electrical resistance | the ability of a material to oppose the flow of electric current; measured in ohms| | Ohmmeter | a device used to measure resistance| | Resistor |a device that reduces the flow of electric current| | Ohm’s law |the straight line relationship between voltage and current; `R = V/I`| ## Static Electricity - `Static Charges`: An unequal number of individual electric charges on the surface of an object. - Basically, the charges are **nearly fixed** on the **surface** of an object. - An object is: |Charge|Condition| |:-----|:--------| |Positively Charged|When number of `electrons` are **less than** the number of `protons`| |Neutrally Charged|When the number of `electrons` are **the same** as the number of `protons`| |Negatively Charged|When the number of `electrons` are **more than** the number of `protons`| - Charge is basically the difference between the amount of protons and electrons, the greater the difference, the greater the charge. - A greater charge between objects is determined by the amount of difference between the protons and electrons in each of the objects. The one with more difference has a greater charge. ## Charging By Friction - When 2 objects of different materials rub against one another, the electrons moves between the objects, one loses electrons and the other gains electrons. - The object that gains electrons becomes negatively charged, and the other becomes positevely charged. ## Triboelectric Series / Electrostatic Series - Different materials have different abilities to hold onto electrons - `Triboelectric Series`: A list of material that is arranged according to their ability to hold on to electrons. ### Table Of Tribolecetric Series Of Common Materials