Structure of the Atom PDF

# Structure of the Atom ## Intro to the Atom - **electricity** can only be understood after understanding **atoms** - atoms are made up of: - **protons** - positively charged - located in the nucleus - **electrons** - negatively charged - orbit the nucleus - **neutrons** - neutral char...

# Structure of the Atom ## Intro to the Atom - **electricity** can only be understood after understanding **atoms** - atoms are made up of: - **protons** - positively charged - located in the nucleus - **electrons** - negatively charged - orbit the nucleus - **neutrons** - neutral charge - located in the nucleus - the nucleus is the center of the atom - electrons orbit the nucleus like planets orbit the sun ## Charge of an Atom - the number of protons and electrons determines the charge of the atom - if protons (+ charge) and electrons (- charge) are equal, there is an equal number of charges - this is called a neutral charge, with no overall charge - if there are more protons than electrons, you get a **net positive charge** - if there are more electrons than protons, you get a **net negative charge** ## Ions - an ion is a charged atom - an ion is formed when an atom loses or gains electrons - the number of protons always remains the same ## Static Electricity - static electricity is an imbalance of electric charge on the surface of an object. - this imbalance occurs when electrons are transferred from one object to another. - this is usually done by **friction** ## Detecting Electric Charges - an electroscope can be used to detect electric charges ### Types of Electroscopes - **pith ball electroscope** - **metal leaf electroscope** - **straw electroscope** - **gold leaf electroscope** - **needle electroscope** ## Law of Electric Charges ### Charges - like charges **repel** - opposite charges **attract** - Neutral objects are attracted to both positively and negatively charged objects ### Induced Charge Separation - a neutral object placed close to charged object will have its electrons attracted to the charge - if the charge is positive, electrons will be pulled to the location nearest the charge - if the charge is negative, the electrons will be pushed away from the charge - the electrons are not lost, only moved around the object ## Electrostatic Series - some substances are more likely to gain or lose electrons than others - this is a **triboelectric series**. - it shows objects with the highest tendency to lose electrons at the top - objects at the bottom have the highest tendency to gain electrons - objects at the top of the list will be **positively charged** when rubbed with objects lower on the list. - objects at the bottom of the list will be **negatively charged** when rubbed with objects higher on the list. ## Charging by Induction - this is a method of charging an object without touching it. - this can be **temporary** or **permanent** - a charged object is brought near a neutral object. - the electrons in neutral object will either be repelled or attracted, causing a separation of charge on the neutral object. - the electrons in the neutral object are **not lost or gained**, only moved around - if the neutral object is then grounded, this reconfiguration may become permanent. ## Grounding - Grounding is the process of connecting a charged object to a conductor in the earth. - this allows electrons to move to or from the Earth, removing the charge on the object. ## Conductors & Insulators ### Conductors - conductors are materials that allow electrons to move freely. - good conductors include: **silver, copper, gold, aluminum, magnesium, tungsten, nickel, mercury, platinum, iron, and germanium.** - fair conductors include: **graphite, the human body, damp skin, acid solutions, salt water, earth, water vapor, air, and silicon** ### Insulators - insulators are materials that do not allow electrons to move freely. - good insulators include: **plastic, ebonite, wood, and glass.** - they are used to prevent electrical shock. ## Electric Discharge - an electric discharge is the rapid transfer of excess charge from one object to another. - this happens when two objects with an imbalance of electric charge are brought close together or come into contact. - this can be seen as sparks or even as lightning ### Lightning - lightning is a large electric discharge that occurs between clouds or between a cloud and the ground. - this happens when there is a large imbalance of electric charge in the atmosphere. - lightning rods are used to provide a safe path for lightning to travel to the ground This document is meant to provide a basic overview of the structure of the atom and static electricity. It is not meant to be an exhaustive study of the subject.