PART I: Earth S Surface Features

SCIENCE BENCHMARKS STUDY GUIDE 1st & 2nd 9 Weeks (August-December 2016) Name:______Date: 12/12/16

PART I: Earth’s Surface Features A. Features Caused by Constructive Processes 1. Key Vocabulary  Deposition – the dropping of sediment or particles by water, wind, or ice  Delta – a deposit of sediment that builds up at a river’s mouth  Floodplain – outer banks of a river where sediment builds up  Longshore Current- a current that moves parallel to the shore  Barrier Island- a long, narrow island that forms along the coast  Sand Dune – a mound of sand piled up by the wind  Glacier – a huge sheet of slowly moving ice  Moraine – a ridge of sediment and rock left behind when a glacier melts  Drumlin – a long, oval shaped mound of soil and rock formed from glacial deposits  Lava – hot, melted rock that pours from volcanoes Magma – hot melted rock before it comes out of the volcano  Fault – a crack in the rock of Earth’s crust 2. Key Ideas  Many of Earth’s surface features form due to constructive processes. Deposits of sediment create some of these features. Others are the result of volcanic activity or movement of earthquakes. Remember that to construct means to create. Both start with a “c”.  Water is the main agent of deposition. Rain washes sediment (rocks and dirt) off the land into rivers. Rivers slow down and make deposits of sediment when joining larger bodies of water such as lakes and oceans. This is why you will see deposition of sediment at deltas near the mouth of a river. Floods also cause deposition along floodplains.  Ocean currents and waves form features such as beaches. Beaches could possibly have been sediment that was once from a mountain thanks to deposition. Some sediment remains on beaches thanks to longshore currents. Barrier islands are also formed by waves and deposition. Georgia’s coast is full of barrier islands such as St. Simons, Jekyll, and Cumberland.  Wind is also an agent of deposition, especially in the desert. Sand dunes can form in deserts and at the beach because of wind.  At the end of the Ice Age most glaciers on North America melted. These glaciers were once thousands of feet thick. Once they melted they left behind soil and rock which formed features such as drumlins and moraines.  Volcanic activity can create landforms. A volcano itself is a mountain built by the release of lava, ash, and rock. When lava cools it forms new land such as Hawaii’s Kilauea Island.  Before lava leaves a volcano, it is called magma. Magma can seep up and flow into spaces between layers of rock. This can form a dome that pushes up rock. As magma domes harden they create mountains.  Earthquake activity can also create land. An earthquake can occur when rock moves underground at a fault (or crack in Earth’s crust). This movement can push land up to form a cliff-like landform called a fault scarp. It can also cause other mountains to rise several inches by shifting other fault lines and landforms that already exist such as the Santa Susana Mountains in California. B. Features Caused by Destructive Processes 1. Key Vocabulary  Weathering – the breakdown of rock at or near Earth’s surface  Mechanical (Physical) Weathering – breaks rocks into smaller pieces without changing it chemically  Chemical Weathering – changes rock into one or more new substances  Erosion – movement of weathered rock from place to place  Desert Pavement – a surface of only bare ground and large stones  Sea Stack – pillars of stone in the sea that form from headlands  Headland – a point of land that juts out into the ocean  Sea Arch – an arch of rock in the ocean that waves have formed by carving away a headland 2. Key Ideas  Some of Earth’s landforms formed due to destructive processes. Remember that to destroy something means to break it down. These processes include weathering and erosion, which break down rock and move it from place to place. Volcanoes and earthquakes can also make destructive changes to the land.  Weathering can happen mechanically (physically) in many ways. These include water seeping into cracks of rocks and then freezing. When water freezes and then warms back up it is contracting and expanding which breaks down rocks, too. Plant roots can also cause rocks to wedge apart and break them down. As tree roots get bigger, for example, they can split rocks apart (like sidewalks).  Weathering can happen chemically in many ways. This means the rocks are changed into new substances. For example, oxygen can combine with iron in rock and soil and causes iron oxide, which is rust. Rust weakens the rock. Another example is when rain mixes with carbon dioxide in the air to cause carbonic acid, or acid rain. Acid rain breaks down rocks (you may see this on grave stones in the cemetery). This also occurs in limestone, which is how many caves form. Living things can also break down rock. Plants called lichen grown on rocks and break them down with acid. Decaying organisms also produce acid as they rot.  Erosion occurs after weathering. Water, wind, glaciers, and ocean waves are agents of erosion and form several types of landforms.  Water is the main agent of erosion. Rivers remove rock and soil from their channels. Over time they carve out river valleys. River valleys are V-shaped. Rivers can also carve out canyons such as the Grand Canyon. In fact, the Colorado River carved out the Grand Canyon over MILLIONS of years of erosion.  Wind erodes by lifting and blowing sand away. It also smashes sand against rocks causing them to smooth out. Wind can only lift sand three feet above the Earth’s surface. This means landforms will seem more worn away at the bottom than top like a mushroom-shape. Desert pavement is a surface caused by wind erosion.  Glaciers can form U-shaped valleys. They can also scoop out holes in the ground that later turn to lakes as the glacier melts. This is how the Great Lakes of Michigan were formed.  Georgia barrier islands are mostly sandy beaches. Erosion is caused by ocean waves. Rocky coasts often have sea stacks, headlands, and sea arches. Headlands begin as land jutting into the ocean. After erosion they turn into sea arches. After even more erosion they turn into sea stacks.  Volcanoes and earthquakes can also be destructive.  When a volcano erupts it can destroy or change the land’s shape such as when Mount St. Helen’s blew its top off by 400 meters in 1980 in Washington state. The shape of volcanoes changes as ash, mud, and lava cover the ground and kill wildlife.  Earthquakes happen when the Earth’s crust shifts at a fault. Cracks can form in the Earth’s surface. Pieces of one side of the fault can be pushed up or fall in forming trenches and cliffs. C. Controlling Constructive & Destructive Processes 1. Key Words  Dam – a structure built across a river to control its flow (used to prevent floods)  Groin – a structure built at right angles, 90 degrees, to the beach (to prevent erosion)  Seawall – a structure built parallel to the shore to absorb waves (to prevent erosion)  Beach nourishment – sand from oceans or rivers nearby is brought in to replace a beach (also called beach reclamation)  Contour plowing – a method in which farmers plow across the sides of hills instead of down slopes to prevent erosion  Terracing – a method in which farmers plant crops on terraces (different levels) built on hillsides to prevent erosion  Storm drain management – a system of drains that prevents flooding during heavy rainstorms to prevent flooding of roads 2. Key Ideas  People use technology to try to control the processes that change the land. In some cases it has the intended result. In other cases, it does not. People use technology to prevent harm from some of the processes that change land and could injure people.  The things people do or the structures they build can affect the natural processes that shape landforms.  Dams are meant to hold back flood waters, but they also hold back sediment that would otherwise be re-deposited. This means floodplains and beaches below a dam may lack sediment. If new sediment is not brought in to replace it at the base of dams, more erosion of the floodplains and beaches could occur destroying animal and plant habitats and recreational areas for humans.  A lot of erosion occurs on coasts. Georgia’s beaches are mainly on the ocean side of several barrier islands. These areas erode frequently, especially after storms. Coastal erosion eats away beach sand and destroys things built along the beach. People build groins and seawalls to prevent erosion of beaches. However, these can also cause erosion to become worse in other areas.  Groins trap sand on their upstream sides, but can cause erosion to become worse downstream. That is because they block sand from reaching those areas.  Seawalls protect the coast behind them but any beach left on the ocean side of the seawall will erode.  Beaches can be restored, or reclaimed, also known as beach nourishment. This is when sand is replaced. Tybee Island and Sea Island, Georgia do this frequently.  Erosion prevention is not only done at the beach. Farmers must prevent erosion so they can have healthy crops for the food they grow that we eat. They do this with contour plowing and terracing. Both methods prevent soil from washing downhill. People also plant vegetation (plants) on hills to hold soil in place (the roots hold onto soil). Windbreaks are rows of plants or fences that are also used to slow down wind and keep it from carrying soil away. Sand dunes are often protected by having windbreaks and vegetation planted there. Dunes protect wildlife (such as sea turtle eggs) and also protect islands from bad storms. This is why we must re-nourish them.  Preventing floods on streets is important for drivers’ safety. You may have noticed storm grates on the side of the road where water drains. This system of storm drain management captures water and moves it off roads.  Scientists cannot control volcanic eruptions or earthquakes, but they have ways to determine when and where these events are most likely to occur.  People can be warned when an eruption or quake is about to happen and save lives.  Scientists cannot predict earthquakes, but they can tell where they are most likely to occur. Detailed maps show where the world’s major fault lines are. People are then told they cannot build or live very close to these fault lines.  Scientists use several types of instruments to monitor active volcanoes. The instruments detect signs that the volcano is about to become active. Before an eruption magma moves upward inside the volcano. This movement causes earthquakes. The sides of volcanoes also swell. As magma rises gases such as carbon dioxide and sulfur dioxide are released. Instruments can detect these changes.  Buildings have special codes by which they must be built to make them strong against earthquakes. Officials have safety tips they can share with the public on what to do if there is an earthquake or volcano to be safe.

Part II: Physical Science: Changes in Matter & Electricity & Magnetism A. Parts of Matter 1. Key Words  Magnify – to use a tool to make things look larger  Mass – total amount of matter in an object  Balance – a tool that measures the mass of an object 2. Key Ideas  All matter is made of small parts. Sometimes you need to magnify an object to see its parts.  The mass of an object equals the total mass of its parts (think: flash light batteries + lens + shell = total flashlight weight)  You can see some parts of matter without magnification (blades of grass, pages in a book)  You need to magnify some objects to see its parts like salt crystals or cells in a leaf  You can magnify objects with a hand lens or magnifying glass or a microscope  Some microscopes are more powerful than others and can see atoms and molecules of matter (electron microscopes)  You can use a balance to measure mass; grams and kilograms are used to report an object’s mass (a paperclip is about 1 gram; a dollar bill is about 1 gram; a liter of milk is about 1 kilogram; there are 1,000 grams in 1 kilogram)  The mass of an object is equal to the sum (adding up) of its parts. For example, if you measure a wooden block as being 25 grams and you make a stack of 5 blocks, the mass would be 5 x 25, or 125 grams. Another example would be if you mix 100 grams of oil and 200 grams of vinegar, the total would equal 100 + 200, which is 300 grams.  Sometimes it may seem like mass is lost, but it isn’t. This happens when matter changes to a different form. For example, if you set a bowl of water down outdoors on a hot day the mass of the water will be less and less due to evaporation. However, the water is not gone. It is now a gas in the air in the same amount as it was as a liquid in the bowl. B. Physical Changes in Matter 1. Key Words  Physical property – a feature of matter that you can recognize with your senses (hear, taste, smell, touch, see)  Physical change – a change in matter in which the type of matter stays the same (tearing paper = still paper)  Texture – feel of a surface (rough, smooth, bumpy, etc.)  Dissolve – break apart (what sugar does in hot water)  State of matter – form that matter has (liquid, solid, gas)  Vibrate – move back and forth quickly  Mixture – two or more kinds of matter mixed but not joined (Taki chips mixed in with Doritos chips)  Filter – paper or other type of screen with small holes in it to separate mixtures (can be a sieve) 2. Key Ideas  Only physical properties change during a physical change.  Some physical properties include: shape, color, smell, mass, weight, length, volume, texture, temperature, hardness, state of matter  Some physical changes include: cutting, bending, tearing, breaking, melting, dissolving, magnetizing, boiling, warming, cooling, freezing, evaporating, separating  Mixing salt, sugar, or hot chocolate into water is a physical change. Each ingredient is still its own substance (salt is still salt, water is still water, etc.)  Matter is made of tiny particles that are always vibrating (solid particles are closer together and don’t vibrate as much; liquid particles are slightly more spaced out and vibrate more than solids; gas particles are the most spaced out and vibrate the most)  Matter can change state by changing its temperature (think: you must freeze ice by taking away heat and melt it by adding heat)  Solids change to liquids by melting  Liquids change to solids by freezing (water does this at 0 degrees Celsius)  Liquids change to gases by boiling (water does this at 100 degrees Celsius)  Gases change to liquids by condensing  A change in state is always physical (NOT CHEMICAL)  A mixture can be separated back into its original substances (because it was only physically changed)  Some ways mixtures can be separated are as follows: filtering (sand vs pebbles), boiling (sugar vs water), gloating (salt vs. pepper), magnetizing (iron filings vs. sugar) C. Chemical Changes in Matter 1. Key Words  Chemical change – a change that forms a new type of matter  Chemical property – a feature of matter that can cause a chemical change 2. Key Ideas  A new type of matter must be formed for it to have been a chemical change.  Examples of chemical changes are burning logs or paper, rotting apples, tarnished silver, or rusted metal  Some clues of chemical changes can be changing color (rotten food, tarnished silver, rusted metal), unusual smell, changed texture, more or less acidic, turning hot or cold WITHOUT being heated or cooled, bubbles forming because a GAS was given off  Note that these clues don’t always mean they are chemical. For example, bubbles could also form from boiling water, which is physical. An object could turn hot or cold by heating or cooling it, which would NOT be chemical.  Cooking an egg and chewing crackers are chemical changes because the object is no longer the same.

Part III: Physical Science: Electricity & Magnetism A. Static Electricity 1. Key Words  Static electricity – a buildup of electric charge on an object  Electron – a tiny particle with a negative charge that makes up an atom (atoms make up all matter)  Electric Force – the push or pull between charged objects  Repel – push between charged objects  Attract – pull between charged objects (opposites attract)  Electric discharge – occurs when charge quickly moves from one object to another (lightening) 2. Key Ideas  Unlike electricity used in your home, static electricity does not flow, but jumps from object to object  Atoms are tiny particles of matter that have one or more electrons  Electrons are a tiny particle inside an atom that has a negative charge  The amount of electrons an object has determines whether or not it has a negative or positive charge  Static electricity is an object’s extra charge  An object with too many electrons has a negative charge  An object with too few electrons has a positive charge  Unlike charges attract (positive and negative)  Like charges repel (positive and positive or negative and negative)  Electric force is somewhat like magnetic force because of the way charges repel and attract like magnetic poles  When two objects rub against each other some electrons may move from one object to the other object  When an object gains electrons it becomes negatively charged and the other object that lost an electron becomes positively charged  If you rub a balloon on your hair electrons move from your hair to the balloon; the balloon becomes negatively charged  Objects don’t always have to touch to become charged; if you bring the balloon near a wall it will push away electrons and the wall will become positively charged causing the balloon to stick to it  If you walk across a carpet in socks on a dry day your body may get a negative charge; if you reach a metal doorknob your body will discharge electricity and you may feel a small shock called static discharge  Lightning is a strong example of static discharge B. Electric Circuits 1. Key Words  Electric current – a flow of electric charge  Electric circuit – a closed path along which an electric charge can flow  Battery – an energy source often used in a circuit  Terminal – a place on a battery where electrons can go in or out  Switch – a device that can open or close a circuit  Closed circuit – a complete electrical path  Open circuit – an electrical path that is not complete 2. Key Ideas  In a solid, the moving electric charges are electrons.  The simplest electric circuit needs an energy source and a material through which electrons can flow easily (conductor)  Batteries provide the push to keep electrons moving in a circuit  A simple battery has 2 parts – a part that gives up electrons and a part that takes them in  A wire must be attached to both parts of a battery to close a circuit  The positive terminal of a battery that allows electrons to go in is on top  The negative terminal of a battery that allows electrons to go out is on the bottom  The wire in a circuit is usually copper, a great conductor  The wire in a circuit is usually coated in rubber or plastic, a great insulator (this keeps you from being shocked)  If a switch is not touching the wire the light bulb will not go off; this means the circuit is open  A circuit must be closed to allow electricity to go through it and turn on a light bulb  A circuit could have more than one light, but those lights might not be as bright because they are sharing electricity (called resistance)  The glow you see in a lightbulb comes from electrons going through the center part called the filament  You can change a circuit by opening or closing it  You can make lights shine brighter by adding more batteries, which give more power C. Conductors & Insulators 1. Key Words  Conductor – a material through which an electric charge can easily flow  Insulator – a material through which an electric charge cannot easily flow 2. Key Ideas  A circuit depends on the flow of electric charge. Charge moves more easily through some types of matter than others. Conductors allow electricity to flow through them easily. Insulators do not.  Charge is carried through solids by electrons. Conductors are made of atoms that hold their electrons loosely. This means the electrons can move freely from atom to atom.  Examples of good conductors are metals such as copper, water, iron, gold, steel, silver and aluminum.  Examples of good insulators are most plastics, rubber, glass, cloth, wood, sand and dry air.  You may recognize the terms insulators and conductors from talking about heat, also. These terms are very closely related. Conductors of electricity also tend to be conductors of heat. For example, a wire is made of copper and so is a cooking pot to heat your food. Insulators of electricity are also insulators of heat. For example, the coating of a wire may be rubber, and the coating of the cooking pot’s handle may also be rubber to protect your hands.  You can use an electric circuit to test whether a material will conduct charge. For example, you could place two wires on a piece of aluminum foil and attach the wires to a battery and light bulb and it would allow the light bulb to light up. If you placed the wires on a rubber eraser instead, the light bulb would not light up because electrons cannot pass through insulators like rubber. D. Magnets & Electricity 1. Key Words  Magnet – an object that can push or pull on iron and a few other kinds of metal without touching it  Pole – the ends of a magnet (north and south)  Repel – push apart  Attract – pull together  Magnetic field – the area around a magnet where it can push and pull on other magnets  Electromagnet – a magnet made by winding a wire with a current around an iron bar 2. Key Ideas  You can see what objects magnets push and pull and how many paper clips they pick up. However, in order to be useful, magnets often need to be strong enough to pick up objects that are heavier than paper clips, and you need to be able to turn them on or off. If you know that magnets are related to electricity, then you can make them do these things!  Some magnets have a bar shape and some have a U-shape, or horseshoe.  When the opposite poles (north and south) of a magnet are near each other they will attract  When like poles (north and north or south and south) of a magnet or near each other they will repel  A magnetic field is all around a magnet, but is strongest at the poles  The push or pull of a magnet is stronger closest to the magnet  The strength of the field is weaker farther away from the magnet  A type of matter can be a magnet if its atoms can line up in a certain way; this only occurs in iron and a few metals  You can use a magnet to turn objects made of these types of matter into weak magnets (for example you can turn paper clips into magnets by rubbing a magnet on them)  An electric current produces a magnetic field  When a current flows through a wire, a magnetic field surrounds the wire  If you form the wire into loops the magnetic field is like that of a bar magnet  Just like a magnet, the wire loops with a current have a north and south pole.  The magnetic field is the strongest at the pole.  You can increase the strength of the magnet by adding more loops to the wire around the metal.  You can also increase the field if you increase the current in the wire.  An electromagnet is made by winding wire with a current around an iron bar.  When the iron bar is placed in the looped wire the iron itself has a magnetic field. This makes the field of the looped wire stronger.  You can make an electromagnet by looping wire around a nail and attaching the ends of the wire to a battery.  The current in the wire causes the iron and wire to be a magnet.  Electromagnets are found in doorbells, computers, audio speakers, telephones, electric motors, and cranes.  A wire coil in an electric motor spins because it is an electromagnet.  Both bar magnets and electromagnets have north and south poles, attract iron and other metals, and have strong magnetic fields at their poles.  Three advantages electromagnets have that bar magnets do not are: they can be turned on and off by turning on and off the current; they can be made stronger or weaker by changing the strength of the battery or number of wire loops; and the direction of the field can be changed by switching the poles or ends attached to the battery.