Be Prepared! Review of Grade 5 Science Curriculum Concepts for the Grade 5 Science SOL Assessment

Transcription

1 Be Prepared! Review of Grade 5 Science Curriculum Concepts for the Grade 5 Science SOL Assessment

2 Scientific Investigation

3 Scientific Investigation How can objects and organisms be classified? (SOL 5.1a) To help in identifying objects like rocks, plants, animals, seashells, or other things, scientists develop classification keys. A classification key gives you two choices to narrow down the object or organisms you are trying to identify. Here is an example of a classification key called a tree diagram: Most classification keys number the choices and do not have pictures. Always start with number 1 and follow the instructions until you reach the solution. Use the key below to identify the balls shown. 1.a Ball is round and spherical go to 2 1.b Ball is elongated go to 3 2.a Ball has hexagons and pentagons on it..soccer ball 2b. Ball has curved lines on it..basketball 3.a Ball has one side with laces Football 3.b Ball has no laces.rugby ball

4 Identify the names of the three creatures below using the classification key. 1a. Creature has feet go to 2 1.b Creature has no feet.. go to 4 2.a Creature has two eyes go to 3 2.b Creature does not have two eyes.. go to 7 3.a Creature has two feet Zeb 3.b Creature has no feet.. Bub 4.a Creature has wheels..go to 5 4.b Creature has no wheels go to 8 5.a Creature has one wheel go to 6 5.b Creature has four wheels. Caz 6.a Creature has one eye Dib 6.b Creature has three eyes Tut 7a. Creature has one arm... Nod 7b. Creature has two arms. Pop 8.a Creature has teeth Roo 8b. Creature has no teeth go to 9 9a. Creature has wings Fig 9b. Creature does not have wings.. Hop

5 What is a hypothesis, and how is it written? (SOL 5.1d) A hypothesis is an educated guess or prediction about what will happen based on what you already know and what you have already learned from your research. A prediction is a guess about what will happen. For example, a group of students was preparing an activity to determine whether certain materials will float or sink when placed in water. One student says, I think the sponge will sink. A hypothesis is a testable prediction. A hypothesis should be written as an If.then. statement. For example, If all light is blocked from a plant for two weeks, then the plant will die. Sandy grows roses along her walkway. Sandy sees that the roses close to the street had more blooms than the roses close to the house. Which statement is a hypothesis Sandy could make about her roses? A. If I grow roses near the house, then they will grow taller than roses close to the street. B. If I grow roses near the street, then they will get more sunlight than roses close to the house. C. If I grow roses near the house, then they will have fewer blooms than roses near the street. D. If I grow roses near the house, then they will have more blooms than roses near the street. Complete the hypothesis statement by making an educated guess: If I eat too many cookies, then.

6 How can we make estimates of length, mass, volume, and temperature using measuring tools? (SOL 5.1b and c) An estimate is a close guess of an actual value. For example, we might not know the number of marbles in a jar, but we can approximate, or guess, a number that is close to the actual number. Estimation is a useful tool for making measures, if we have had experience using a tool. About how tall is the tree in the diagram below? A. 10 feet B. 20 feet C. 40 feet D. 80 feet About how much liquid is in the graduated cylinder? A. 5 ml B. 10 ml C. 15 ml D. 20 ml

7 About what is the temperature in degrees Celsius ( C) on thermometer A? A. 10 C B. 15 C C. 50 C D. 60 C About what is the temperature in degrees Celsius ( C) on thermometer B? A. 30 C B. 28 C C. 2 C D. 0 C What are constants in an experiment? (SOL 5.1f) The constants in an experiment are the things that are not changed throughout the experiment. Constants are all the factors that remain the same throughout the experiment. Students planted bean seeds in two cups and placed the cups on a sunny window sill. One cup was given 10mL of water and the other cup was given no water. What should be kept constant in this experiment?

8 What is the difference between an independent variable, a dependent variable, and a constant? (SOL 5.1e and f) An independent variable is the factor in an experiment that is altered by the experimenter. The independent variable is purposely changed or manipulated. A dependent variable is the factor in an experiment that changes as a result of the changes made to the independent variable. Everything else in an experiment should be the same, or constant. Two students wanted to find out which one of their toy race cars would go the farthest. They let each car roll down a ramp and then measured how far the car rolled. Which of these should be held constant if they want a fair test of their cars? A. the height of the ramp B. the weight of the ramp C. the length of the cars D. the shape of the cars A student set up an investigation to test the effect of light color on plant growth. What is the independent variable in the experiment? Red Light Blue Light Yellow Light

9 Force, Motion, Energy, and Matter

10 Sound How is sound created and transmitted? (SOL 5.2 a and b) Sound is a form of energy. It is produced by vibrating matter. Vibrations are the back-and-forth movements of an object. Sound is a series of vibrations traveling in waves. You can t see sound waves, but when you pluck a guitar string, the string vibrates, causing sound. Musical instruments aren t the only things that make sound. Striking the head of a nail with a hammer causes sound vibrations, too. When we talk, sound waves travel in the air. All sound vibrations travel in compression waves. As a compression wave moves, molecules of air or other matter are pushed together, or compressed. Then the molecules spread apart. Sound energy moves away from its source as this bunching and spreading of molecules is repeated over and over. This is what a sound wave would look like if we could see it. Here you can see the sound waves traveling from the speaker through the air. The molecules move back and forth, bunching up in some places (compression) and in some parts spreading out. Waves consist of curving lines that go up and down as they move away from the sound source. Each high point is called a crest (or peak) and each low point is called a trough. A wavelength can be measured from any point on a wave as long as it is measured to the same point on the next wave. In this picture, the wavelength is being measured from peak to peak.

11 Some sound waves are tight and tall. This wave has a lot of energy. The molecules are vibrating very fast, causing the molecules to bunch up a lot. Some sound waves are long and flat. This wave does not have as much energy. These molecules are not vibrating as much, causing the molecules to not bunch up as much. Amplitude is the amount of energy the wave has and describes its volume. The tight, tall wave would cause a loud sound to be heard, while the long, flat wave would cause a soft sound to be heard. The tight, tall wave also has a higher frequency. This means that a lot of wavelengths travel past a certain point in a given amount of time. Frequency determines the pitch of a sound how high or low it is. The tight, tall wave has a higher pitch. This might be the sound wave produced by a bird. The long, flat wave has a lower frequency. This means that not as many wavelengths travel past a certain point in a given amount of time. The pitch of this wave is low. This might be the bark of a large dog. Which diagram shows the wave with the highest frequency? A. B. C. D.

12 Which wave has the longest wavelength? A. B. C. D. A student plans to investigate how sound changes when four bottles with different amounts of liquids are tapped with a spoon. Which bottle will have the lowest pitch? A. B. C. D. Hint: When the student taps the glass, the glass vibrates. The vibrations have to travel through the glass and through the liquid. What is the ability of solids, liquids, and gases to transmit sound? (SOL 5.2c) Sound only travels if there are particles that the waves can cause to vibrate. Most of the sound you hear is through air. Air and other gases have particles that vibrate as sound energy hits them. When there is no air (a vacuum), there is nothing for sound waves to travel through. So, when a rock is dropped on the moon, there is no sound! Sound also travels through solids and liquids. Sound travels fastest through solids because the particles in solids are close together. Sound travels slower in liquids, and slowest in gases.

13 Which material will sound travel through the fastest? A. water B. air C. steel D. cloth What are some uses of sound waves? (SOL 5.2d) Sound insulation contains tiny air cells. Sound is absorbed as Wall Insulation the cells trap sound waves. This keeps the sound inside the room. Musical There are many different types of instruments, and they all Instruments cause vibrations in a different way. There are percussion, string, wind, and electronic instruments. Music Studios Engineers use knowledge of sound as they record music, voices and other sounds in the studio. Movie Theaters Sound must be amplified (given lots of energy). Engineers place speakers in certain places so everyone can hear clearly. Sonar Sound Navigation and Ranging: Sound waves are sent through water and bounce off anything in their path. Used to find shipwrecks and map the ocean floor. Animals Bats, whales, and dolphins use echolocation: they emit pulsed sounds of high frequency to fly, swim, and locate food. Sonar Stringed Instrument Bat Echolocation

14 Light What is light, and how does it travel? (SOL 5.3a) Light is a form of energy that moves in waves and can travel through space. Light waves are transverse waves. As these waves move forward, the energy is carried perpendicular to their forward motion. (Sound waves are compression waves their energy is carried parallel to their forward motion.) Light Waves = Perpendicular (Transverse) Sound Waves = Parallel (Longitudinal) Light can move through a vacuum because it does not need matter to transmit its energy. Light waves travel in straight paths called rays. A ray is the straight line that represents the path of light. A beam is a group of parallel waves. Light travesl extremely fast. What is the visible spectrum? (SOL 5.3b) The electromagnetic spectrum is a range of light waves organized by frequency and wavelength. At one end are the waves with long wavelengths and low frequencies. On the other end are the waves with short wavelengths and high frequencies. The part of the electromagnetic spectrum we can see is called the visible spectrum. This is the light humans can see. It looks white to our eyes, but is really many different colors.

15 We see visible light as the colors of the rainbow. Each color has a different wavelength: red has the longest wavelength and violet has the shortest wavelength. A prism can be used to separate visible light into the colors of the rainbow (ROYGBV). The prism disperses (or separates) the light. When the different wavelengths of light pass through the prism, they bend at different angles. By passing light through a prism, you can tell A. the mass of the prism B. that white light is actually a mixture of different colors C. the original source of the light D. that blue light is brighter than red light What is the difference between opaque, transparent, and translucent materials? (SOL 5.3c) Transparent light passes through these materials easily. Translucent light passes through these materials partially. Opaque light doesn t pass through these materials at all. Identify each of the following as transparent, translucent, or opaque. A. wood G. thin paper B. bricks H. wax paper C. clear glass I. clear plastic food wrap D. aluminum foil J. thin fabrics E. air K. clean water F. frosted glass L. thick paper

16 What are reflection and refraction? (SOL 5.3d and e) Light travels in a straight path until it hits an object, where it bounces off (is reflected), is bent (is refracted), passes through an the object (is transmitted) or is absorbed as heat. Reflection Refraction Transmission This duck sees its reflection because the light waves are bouncing off the water in the pond. This leprechaun is refracting, or bending, white light as it goes through the prism. The light is traveling through the windshield, and the air in the car heats up. The flower s stem appears larger under water because the water A. absorbs light B. produces light C. repels light D. refracts light

17 Matter What is matter and in what phases does it occur? (SOL 5.4a and b) Matter is anything that has mass and volume. This page is made of matter; you are also made of matter. Air is matter, because it has mass and volume. Mass is the amount of matter in an object. It is different from weight. Mass does not change; a person will have the same mass on Earth, Mars, or our moon. Weight changes with gravity. There is a different gravitational pull on this here on Earth than there is on our moon, so a person will weight different amounts on the Earth and moon. Matter can exist in several forms which are called phases. The three basic phases of matter are: Solid Liquid Gas Has a fixed shape Takes the shape of the container it is in Takes the shape of the container it is in Has a definite volume Has a definite volume Expands to fit the volume of the container it is in Particles tightly packed together; little movement Particles not as closely packed together (flows) Particles can move past each other easily (flows) As its temperature increases, many kinds of matter change from a solid to a liquid to a gas. As its temperature decreases, that matter changes from a gas to a liquid to a solid. An example of this is water. As a solid, water is ice. As a liquid, it is liquid water. As a gas, it is water vapor.

18 Gallium is a metal that melts at 30 C. A person, whose body temperature is 37 C, held a cube of gallium for five minutes. What most likely happened to the gallium? A. it changed to a gas B. it changed to a liquid C. it will become a mixture D. it will become vapor When ice cream is left out of the freezer, the ice cream changes from a A. solid to a gas B. gas to a liquid C. solid to a liquid D. liquid to a gas Which of these correctly describes how water changes phases? A. Liquid water melts to form ice. B. Liquid water boils to form water vapor. C. Ice condenses to form liquid water. D. Water vapor evaporates to form liquid water. What is matter made of? (SOL 5.4c) All matter is made of particles that are too small to be seen by the naked eye. There are many kinds of matter. These particles are called atoms. An element is the type of matter that is made of just one kind of atom. Atoms are made of smaller parts. In the center or nucleus, there are protons (+) and neutrons (red and blue). Electrons (-) (black) speed through an area around the nucleus called the electron cloud.

19 The atom in the picture above has electrons, protons, and neutrons. It is an atom of the element Litium. Atoms of other elements have different numbers of electrons, protons, and neutrons. Oxygen has 8 protons, 8 neutrons, and 8 electrons; Hydrogen has 1 proton, 1 neutron, and 1 electron. Draw and label a Carbon atom Use the information provided to draw and label a carbon atom. Protons: 6 Neutrons: 6 Electrons: 6 What are molecules and compounds? (SOL 5.4d) Sometimes atoms of different elements combine to make compounds. The smallest portion of a compound is a molecule. Here is a molecule of water. It is made of atoms of Hydrogen and atom of Oxygen. Here is one molecule of water. This is a group of water molecules in the compound called water.

20 We write the name for water as H 2 O. Another compound is salt, NaCl. It is made of sodium (Na) atoms and Chlorine (Cl) atoms. Match the words with their meanings (You will have one left over). Nucleus Atom Proton Element Neutron Electron Compound The smallest part of an element. The particle that moves around the outside of an atom. Formed from at least two types of atoms. The positively charged (+) part of the nucleus. The central part of an atom. Contains only one kind of atom. What are mixtures? (SOL 5.4e) A combination of two or more substances together that can be separated again is called a mixture. For example, a fruit salad is a solid mixture of bananas, strawberries, peaches, and blueberries. An example of a liquid mixture is a strawberry smoothie drink, which is a combination of strawberries, milk, yogurt, and ice. It would be hard to separate the parts of a smoothie, but easy to separate the parts of a fruit salad! Sometimes one part of a mixture dissolves in the other part of the mixture. When something dissolves, it breaks up into particles so tiny they can t be seen even with a microscope. These mixtures are called solutions. Most solutions are liquids, like salt water. Circle the substances below that are solutions.

21 Living Systems

22 What are the parts of a cell? (SOL 5.5a) Living things are made of cells. Cells carry out all life processes, such as growing and reproducing. Cells are too small to be seen with the eye alone. By using a microscope, many parts of a cell can be seen. (Animal cells have small vacuoles that aren t seen on this picture; plants have one large vacuole.) Identify the part of the cell described, then tell if it is in a plant cell, animal cell, or both. (The first one is done for you.) store water, nutrients, and wastes. (both) surrounds the cell and controls what enters and leaves the cell. use energy from sunlight to make sugar. jellylike substance that holds the cell s parts. directs all of the cell s activities. is stiff and gives the cell its square shape. Why do plants need to have cell walls around their cells?

23 How can living things be grouped? (SOLs 5.5b and 5.5c) Organisms that share similar characteristics can be organized into groups in order to help understand similarities and differences. Living things are grouped, or classified, into three main groups called domains. Within domains are kingdoms. Domain Eukarya Protist Kingdom Fungi Kingdom Plant Kingdom Animal Kingdom One-celled organisms (except bacteria) and algae Mushrooms and Molds Nonvascular Plants do not have special tissue to transport food and water No backbones (Invertebrates) Worms Arthropods (insects, spiders, starfish, snails) Vascular Plants have special tissue to transport food and water Backbones (Vertebrates) Amphibians Fish Reptiles Birds Mammals, including humans

24 Match the group with the description by drawing a line between them: A. Animal Makes its own food B. Plant Lacks a backbone C. Fungus Feeds on dead or decaying matter D. Protist Has a backbone E. Invertebrate Has specialized tissue for food & water F. Vascular Many cells; cannot make its own food G. Nonvascular Single celled and small H. Vertebrate Lacks specialized tissue for food & water The jellyfish is an invertebrate because it lacks A. eyes B. bones C. blood D. Cells Circle the vertebrate: Trees, wildflowers, and grasses are all considered to be A. vascular plants B. woody plants C. nonvascular plants D. nonwoody plants

25 Interrelationships in Earth/Space Systems

26 What are geologic characteristics of the ocean? (SOL 5.6a) Oceans cover about 70% of Earth s surface, almost three times the area that land covers. If you could hike across the ocean floor, you would begin on the coastal plain and enter the water onto the continental shelf. At the edge of the shelf, the continental slope drops sharply. The drop levels out gradually where sediment has collected at the bottom of the slope. This is the continental rise. In the deep ocean, you reach a vast, flat region of abyssal plain. After a long trek across the abyssal plain, you find another steep drop. This oceanic trench is a deep valley in the abyssal plain. You also cross an underwater range of mountains and valleys called a mid-ocean ridge. Some volcanic mountains rise so high, they break through the surface of the water. The exposed mountaintops are islands. Label the parts of the ocean floor. Which structure (identified by its letter) will most likely become an island? Which best describes the continental shelf? A. a flat underwater valley B. a region of mountains in the deep ocean C. a shallow area of sediment near the shore D. a region with high water pressure

27 What are physical characteristics of the ocean environment? (SOL 5.6b) Make-up of ocean water Ocean water is a mixture of gases (air) and dissolved solids (salts, especially sodium chloride). The saltiness of the water is its salinity. The salinity of the water varies in some places depending on rates of evaporation and amount of runoff from nearby land. As the water deepens in the ocean, the water pressure becomes greater. At a certain depth, water pressure is too great for divers to withstand. Also, the deeper the water, the less sunlight reaches to warm it. Waves, currents, and tides Surface waves are caused by wind pushing against the surface of the water. As waves approach the shoreline, the bottom of the wave drags on the sea floor and slows. The top of the wave continues to move forward and breaks. An ocean current is a steady flow of water in a regular pattern in the ocean. Currents flow like rivers in the ocean, moving large amounts of water long distances. Temperature, salinity, and the shape of the ocean floor and shoreline play a role in currents. Salt increases water density, so saltier water is denser and will tend to sink. The Gulf Stream is a warm water Atlantic current that flows from the south to north along the eastern coast of North America, past Virginia. It then moves across the ocean toward Europe.

28 Tides are changes in the height of ocean water. The pull of the Sun s and moon s gravity causes ocean tides. When the moon is above an ocean, it causes high tide on that part of Earth and on the opposite side, too. In the parts of the ocean between the two areas of high tide, the water level is lower. At those places, a low tide occurs. At most beaches, there are high tides and low tides every day. The tides make a cycle. What are ecological characteristics of an ocean environment? (SOL 5.6c) The ocean supports many different ecosystems, as does the land. On land, different ecosystems are separated by natural boundaries, such as mountains or deserts. In the ocean, ecosystems are also separated by barriers or boundaries. However, these are boundaries of temperature, salinity, and depth. Intertidal Zone Near-shore Zone Open Ocean High tide, low tide, tide pools, plants, anemones, barnacles, shore, beach Coral reef, birds, jellyfish, sharks, dolphins, sunlight, whales, plants Whales, squid, hydrothermal vents, tubeworms, dark, crabs, shrimp, cold, little oxygen The intertidal zone is the area between the high tide and low tide lines. It has tide pools (or rock pools) that hold water while the tide is low. The shallow seas (or near-shore area) is where coral reefs are found. Sunlight warms the water and supports lots of life.

29 The open ocean has many of the same animals that live in the near-shore area. In the deep ocean, hydrothermal vents volcanic spots are found on the ocean floor. As you move deeper into the ocean, sunlight decreases and the temperature drops. This is an example of a food chain in the ocean. Plankton are microscopic one-celled organisms that are either plant-like (make their own food using the energy from the sun) or are animallike (eat other plankton). The ocean floor A. is always a flat bed of sand. B. has mountains, plains, and ridges like land surfaces. C. is covered by the same amount of water everywhere. D. covers less area than land. The diagram shows a model of the ocean floor. Which letter identifies the continental slope? A. 1 B. 2 C. 3 D. 4

30 Acorn barnacles are animals that live 1 to 2 meters above low-tide level. What ocean zone are they found in? A. open ocean B. intertidal C. shallow seas D. near shore Here is a picture of part of a coral reef. What is a coral reef? A. a rock B. an ecosystem C. an underground cave D. a hydrothermal vent At which location are oceans the deepest? A. mid-ocean ridge B. abyssal plain C. ocean trench D. volcanic island What do the arrows on the map represent? A. size of waves B. water density C. time between tides D. ocean currents

31 Earth Patterns, Cycles, and Change

32 What are the different rock types, and how are they formed? (SOL 5.7a, f) A rock is a natural solid that is made of one or more minerals. Rocks move and change over time. After rock forms, it does not stay the same forever. The rock may be broken down by water or wind, or it may be heated and squeezed or melted by the pressure inside Earth. Depending on how rocks are formed, they are classified as sedimentary, igneous, or metamorphic: Type Description Examples Characteristics Sedimentary Layers of sediment (particles of rock) that are cemented together under pressure. Sandstone Shale Conglomerate Rock salt Limestone May contain fossils; layers Igneous Melted rock called magma or lava cools and hardens. Form deep inside Earth as magma slowly cools. Metamorphic Heat and pressure change the physical and/or chemical makeup of sedimentary or igneous rock. Coal Basalt Granite Gneiss Slate Large or small crystals, depending if magma or lava A changed rock; banding may occur Earth s surface is constantly changing because of weathering, erosion, or deposition. Weathering is when pieces are worn off the surface of a rock. Weathering creates clay, sand, rock fragments, and substances from rocks that are dissolvable in water. Earth s surface also changes through erosion. This is when water, wind or moving ice (glaciers) breaks off pieces of rock and carry them somewhere else. Deposition occurs when the moving pieces are dropped in one place and become sediments. If these sediments are pressed together, they become sedimentary rock.

33 What is the rock cycle and how do transformations between rocks occur? (SOL 5.7b) Read the each statement. What type of rock is being described in each statement? Use M for metamorphic; S for sedimentary; and I for igneous. Forms when sediments are cemented together. Forms when rock is placed under great heat and pressure Forms when magma or lava cools The longer it took to form, the larger its crystals will be May contain fossils Can be found in mountain ranges Examples include marble, quartzite, and gneiss Examples include granite, basalt, and rhyolite Examples include sandstone, limestone, and shale

34 Which of the following events occur in the formation of an igneous rock? A. Cooling B. Banding C. Layering D. Weathering What is the main difference between igneous rocks and metamorphic rocks? A. Metamorphic rocks are always banded. B. Metamorphism does not involve melting. C. Igneous rocks cannot be metamorphosed. D. Igneous rocks are smaller than metamorphic rocks. Which of these processes would change limestone into marble? A. Heat and pressure B. Melting and cooling C. Volcanism and erosion D. Weathering and cementation What can we tell about Earth s history based on fossil evidence? (SOL 5.7c) Earth is about 4.6 billion years old. Much of what we know about Earth s history has come from the discovery of fossils, which are preserved organisms or imprints of organisms (such as footprints, or marks of feathers, and scales). From fossils and other evidence, scientists think that life on Earth began around 3.7 billion years ago.

35 Fossils form when an organism dies and is buried under mud or other sediment. Usually, the softer parts of the organism decompose, but harder parts, like bones and teeth, may be preserved or protected. Based on the diagram, which layer contains the second-oldest fossils? A. 1 B. 2 C. 3 D. 4 The presence of an animal fossil in a rock gives evidence of A. what hunting behaviors the animal used. B. how many babies the animal had. C. exactly when the animal was born. D. the time period the animal lived in. Scientists find fern (a type of plant) fossils in a rock. What could the scientists infer from the fossils? A. The area was underwater. B. The area was once a forest. C. A volcano killed all the wild life there. D. There was not enough sunlight to support life.

36 What is the basic structure of Earth s interior? (SOL 5.7d) Earth is a sphere made of a series of layers, like the layers of an onion or baseball. Layer Description Cut-Away View of Earth Crust Hard and made of many minerals. It is thinnest under the oceans and thickest under mountains. Mantle Contains some liquid rock but is mostly solid. High heat and pressure in the mantle cause it to flow slowly like warm plastic. Core Inner core is solid iron and nickel Outer core is molten, liquid metal. Which of these statements best describes the relationship between Earth s layers? A. The hottest layers are closest to the core. B. The more liquid layers are closest to the crust. C. The lightest layers are closest to the core. D. The more metallic layers are closest to the crust. Earth is composed of four layers. Many scientists believe that as Earth cooled, the denser materials sank to the center and the less dense materials rose to the top. The least dense layer is the A. Crust B. Mantle C. Inner core D. Outer core

37 How does Earth s surface change as a result of plate tectonics? (SOL 5.7e) Earth s crust is a hard shell of rock, but it is not one solid piece. Many pieces of crust, called plates, fit together like a jigsaw puzzle. The plates rest on Earth s mantle. As the Earth s mantle flows like warm plastic, the plates move, too. The plates move too slowly to see, however. The theory that Earth s crust is divided into plates that are always moving is called plate tectonics. Some plates contain continental crust, some plates contain oceanic crust, and some contain a combination of the two. In some places, the plates are spreading apart; in other places, the plates are moving toward each other. Plates can also slide past each other. A fault is a boundary where one plate meets another. There are three kinds of boundaries. Type of Boundary Description Geologic Features Divergent boundary Plates moving in opposite directions Underwater divergent boundaries can cause magma to rise (a volcano), forming ranges like the Mid-Atlantic Ridge. Or they can form Convergent boundary Plates moving toward each other and collide, causing them to buckle deep ocean trenches. Convergent boundaries often result in mountain ranges, such as the Appalachian mountains. Sliding boundary Plates slide against each other horizontally Earthquakes can form along sliding boundaries, often called strike-slip or transform boundaries.

38 As plates move, the pressure becomes too great, and the rock on one side of the fault suddenly snaps free and slides past the rock on the other side. This release of energy and shaking is an earthquake. The point inside Earth where an earthquake begins is called the focus. Energy from the earthquake travels away from the focus in waves. The point on Earth s surface directly above the focus is called the epicenter. Earthquake motion is the most severe at the epicenter. The liquid rock below Earth s surface is called magma. At boundaries where plates are either moving toward each other, pulling away from each other, or at hotspots in the middle of plates, openings in the crust can occur. A volcano is an opening that allows magma to reach Earth s surface. Lava is the molten rock that erupts from the volcano along with ash and hot gases. What does the theory of plate tectonics state? A. Earth s mantle is solid. B. Earth s crust is divided into parts that move. C. Earth s inner core causes changes in the crust. D. Earth s outer core is liquid, and its inner core is solid. The shale layers in the diagram were broken and separated by movement along the fault. What also most likely occurred as these rock layers moved along the fault? A. Formation of deep caves B. Erosion of lower layers C. Volcanic eruption D. Earthquake

39 Why do earthquakes occur along faults? A. Rocks along a fault are under pressure. B. Rocks along a fault are stable. C. Rocks along a fault are easily eroded. D. Rocks along a fault are easily weathered. How do humans change Earth s surface? (SOL 5.7g) Humans alter and affect the world around them. This includes the physical shape of the world. Humans have a great impact on weathering and erosion, and most often humans increase the amount of erosion. Humans do this by: 1. Changing the flow of rivers and streams: humans create dams and reservoirs (large bodies of water) for power or drinking water or crop irrigation. Levees are often built to protect homes, farms, and factories. Since rivers are a force for erosion, changing their flow affects erosion. 2. Cutting down trees: trees help break up and block the wind. When trees are cut down, as for farms, it reduces this protection against wind erosion. 3. Reducing vegetation: the roots of many plants, such as trees and grass, help to hold soil in place. When people clear land for development, this protection is reduced. 4. Increasing run-off: run-off is rain water that runs across the surface of the land instead of being absorbed. Concrete, blacktop, asphalt are materials that do not absorb water the way soil does. When people pave over areas to create towns and roads, they decrease the absorption of water by the ground, which increases the amount of moving water.

40 Which of the following is not an example of human impact on Earth s surface? A. The creation of a new highway. B. An increase in the amount of rain. C. The removal of a hillside near a housing development. D. Building a new power plant near a river. Which of these is a positive way human have an impact on the physical world? A. Clearing land to build new homes. B. Building a new highway through an area. C. Cutting down trees to make farmland. D. Planting new trees where old ones were cut down. What is an example of humans changing Earth s surface? A. Erosion B. Mining C. Plate tectonics D. Weathering