Third Grade CRCT Study Guide for Science

1. Third Grade CRCT Study Guide for Science

2. Heat • Forms of Energy: Chemical Solar Electrical Mechanical Nuclear • Energy: the ability to do work or cause change. It can be found in several forms. • Doing work requires energy. Living things cannot survive without energy, and machines cannot work without energy. A person can get no more work out of a machine than the energy that has been put into it. Due to friction, the work produced is usually less than the energy used. There are many forms of energy, each of which can be transformed from one form to another. Electrical energy can be produced in several ways, such as from chemicals that produce electric current in a battery or from water power turning generators. Heat energy is produced by combustion of chemicals or by heating a wire with electrical energy until it glows. Mechanical energy is produced by moving objects or substances. Wind, water (including steam), and muscles can produce mechanical energy. One important form of energy is produced by the sun. Solar energy provides heat and light energy necessary for all life on our planet. Chemical energy is formed when chemicals that react with oxygen or other chemicals, are transformed into heat, light, sound, and movement. Our bodies use the chemicals in food for mechanical and heat energy. Nuclear energy is often referred to as the energy of the future. It is the nuclear energy of the sun that produces its light and heat. The fusion or fission of atomic particles can release tremendous amounts of energy. Nuclear fission reactions can be controlled and are used to produce steam for turbines to turn electric generators. However, radioactive waste products from nuclear energy are still an environmental problem.

3. Conduction –to transmit heat, electricity, or sound. The movement of thermal energy. Thermal means having to do with or producing heat. Conductor is material in which thermal energy moves easily through. • Convection –The transfer of heat by the movement of air, gas, or heated liquid between areas of unequal density. It’s thermal energy moving from one place to another when changing from a liquid to a gas. • Radiation –The process of emitting radiant energy in the form of particles or waves. Radiation is when thermal energy moves without touching anything. • Radiate- To move out in rays, such as heat moving through the air. • Thermometer- A tool used to measure how hot or cold something is. • Thermostat- Turn a furnace and air conditioner off and on. • Identifies and discusses alternative heat sources such as synthetic fuels and geothermal / nuclear / solar energy and associates products with their sources. • Synthetic –man made; artificial • Geothermal –relating to the internal heat of the earth. • Nuclear –Pertaining to and resembling a nucleus; atomic energy. • Solar energy –Utilizing the sun for power or light.

4. Heat and Energy • Energy is the ability to cause change. There are many types of energy. Electricity is one type of energy that people make from things found in nature. Electricity can be made from coal, oil, water, wind, or the sun. Energy that comes from the sun is called solar energy. We can conserve, or save, energy by turning off lights and not wasting electricity. • Heat energy is one type of energy called thermal energy. When objects rub together, heat energy is produced. Friction is the force between two moving objects that produces heat. Rubbing your hands together is an example of this. • Heat is fast moving molecules. We can measure how hot or cold something is by using a thermometer. Heat always moves from a hot place to a cold place. Heat passes through objects. Objects that allow heat to pass through them easily are called conductors. Metal is a good conductor. We can tell because metal gets really hot or really cold quickly. Objects that do not allow heat to pass through them easily are called insulators. Insulators can be cloth, plastic, rubber, or any material that does not allow heat to move through it easily.

5. ROCKS AND MINERALS • Rocks are made from minerals. A mineral is an object that is solid, is formed in nature, and has never been alive. Minerals can be different colors, and they can also be soft or hard. We can usually tell what type mineral it is by looking at its properties. Some properties of minerals are hardness, texture and color. Some common minerals are quartz, talc, and sulfur. There are also different uses of minerals. Halite is used to make salt, talc is used in powder, and sulfur is used in medicine. Many other minerals such as gold, silver, emeralds, and diamonds are used to make jewelry. • Rocks are made from different minerals. It takes many, many years for a rock to form. There are three types of rocks: Igneous, Sedimentary, and Metamorphic. Igneous rocks are formed from lava or melted rock that cooled and hardened into rock. There are many different igneous rocks. Examples include granite, pumice, basalt, and obsidian. Granite is the most common rock in Georgia. • Sedimentary rocks are form when sand, pebbles, leaves,, clay, animal remains, or other material settle into layers. These layers are pressed together under the ground and after many, many years, a sedimentary rock forms. Some common sedimentary rocks are limestone, sandstone and shale. • Metamorphic means change, so metamorphic rocks are rocks that have changed from one type into another type. Heat and pressure inside the earth can cause a rock to change types. For example, limestone, a sedimentary rock, can become marble. Some common types of Metamorphic rocks are marble, slate, schist and gneiss. Each type of rock can be changed into another type of rock. This changing process is called the rock cycle.

6. Minerals • Mineral- an object that is solid, is formed in nature, and has never been alive • *There are about 3,000 different types of minerals. • *Hardness, color, and shape are examples of a mineral's properties. Minerals give rocks their color, hardness, texture, and luster. uses of minerals 1. salt for food comes from Halite 2. iron comes from hematite and it's used to make steel for buildings, airplanes & other things 3. jewelry: gold, diamonds, ruby , emerald 4. money: copper for pennies 5. "lead" or graphite for pencils 6. quartz is used to make glass 7. aluminum comes from bauzite and is used to make products like baseball bats, cooking pots... 8. flourite is used in toothpaste 9. talc is used in baby powder 10. silver has many uses 11. sulfur is used in medicine

7. Rocks • Rock- a solid made of minerals • The Earth is made mostly of rocks. • Crust- solid outside layer of the Earth you can see. • Mantle-The middle layer of the Earth. It's so hot that some of the rocks have nearly melted. • Core-The center of the Earth. It's hotter than the mantle. It's made of iron. It's so hot that the iron is liquid.

8. Three types of rock: • Igneous rock- form from melted rock (lava) has cooled and hardened into rock. Example: pumice, granite,obsidian, basalt, mica • Sedimentary rock- forms from material such as sand, pebbles, leaves, clay, animal remains, that settle into layers. The layers are squeezed together until they harden into rock. Example: limestone, sandstone, shale, conglomerate, coquina, gypsum • Metamorphic rock- forms from igneous, sedimentary, or other metamorphic rock that have been changed by heat and pressure in the ground. Example: marble, gneiss, schist, slate, quartzite

9. Each type of rock can be changed into the other type of rock. This process of changing is called the rock cycle. How people use rocks • silicon chips for video games, computers, satellites, microwave ovens • jewelry • roads are paved with rocks • buildings & statues are made of rocks (marble, limestone, granite)

10. Plant Facts • Moving pollen from one flower to another is pollination. • Plants change water and carbon dioxide into food(sugars) during photosynthesis. • The life cycle of a plant (how it grows and develops) is called germination. When the seed breaks open it germinates. • The seed coat provides a protective layer for the seed. • Plants are made up of small units called cells. • Photosynthesis: A plant's roots take in water from the soil. Water goes through the stem to the leaves. A gas, carbon dioxide goes into tiny openings in the leaves. The green material in the leaves is called chlorophyll. The chlorophyll traps energy from the sunlight. Plants use the energy to change water and carbon dioxide into plant food (sugars) and oxygen. The oxygen goes into the air. Plants use the food(sugars) to live and grow. Ways people use plants: There are many ways people use plants. Here are only a few: food, medicine, oxygen, wood for homes, furniture, paper. Understand ways seeds are spread: Water, wind, animals, people.

11. Fossil- remains of plants or animals that have hardened into rock. There are different types of fossils. 1. body parts, such as bones or teeth or shells, that have turned to stone 2.animal track fossils, plant fossils • *Scientists can use fossils to understand how dinosaurs looked and lived long ago. • How fossils form: They often form in sedimentary rocks. Remember- these animals & plants lived long ago. • The soft parts of the animal decompose and hard parts of the animal are slowly buried under layers of sediment. • A mold is the shape of a plant or animal left in sediments when the rock formed. • A cast forms when mud or minerals fill a mold. The cast has the exact shape of the animal that made the mold. • Fossil imprints are molds of leaves or other thin objects like feathers or wings. The actual parts decomposed long ago.

12. Magnets • A magnet is an object that attracts things that contain iron. Objects that do not contain iron, like paper, glass, or plastic, are not attracted to a magnet. Magnets are used in many electronic devices, like computers and motors. Magnets can also be used to make electricity. • To attract means to pull toward something. Magnets have two ends called poles. One pole is the north seeking pole and the other is the south seeking pole. When you put two magnets together, the north pole of one magnet is attracted to the south pole of the other magnet. The opposite poles attract. If you put two north poles together, or two south poles together, they repel each other. To repel means to push away. • An object is magnetic if it attracts things that contain iron. Every magnet has a magnetic field. The magnetic field is the area around the magnet where the magnet attracts iron objects. You can make a temporary magnet by rubbing an iron object on a magnet. The temporary magnet will behave like a magnet for a short time.

13. Landforms Earth’s surface has many natural shapes, or features, called landforms. There are many types of landforms. A mountain is a place on Earth’s surface that is much higher than the land around it. Some parts of Earth’s surface are low areas. A valley is a lowland area between higher lands such as mountains. A canyon is a deep valley with very steep sides. A plain is a flat area on Earth’s surface. The middle of the United States is a large plain. A plateau is a flat area higher than the land around it. In some places plateaus have steep sides. They look like tables made of rock. You might see another kind of landform at the seashore. A barrier island is a thin island near a coast. Barrier islands have wide, sandy beaches. A peninsula is land that has water around most of it. Think of Florida!

14. Soil Soil is a mixture of different materials. Weathered rock is part of soil. The process of weathering is called erosion. Wind and water are two ways rocks can become weathered. The weathered rock contains minerals that make up most of soil. Soil also contains humus. Humus is the part of soil made up of decayed parts of once living things. There are different types of soil and they can be different colors. The color depends on what is in the soil. Black soils have a lot of humus. Clay is another type of soil. Clay is made up of small grains with small spaces between the grains. Clay becomes sticky and clumped together when it gets wet. Sandy soil has larger spaces between the grains. This allows water to drain quickly from sand. Plants grow best in loam. Loam is rich soil with a lot of humus. Loam also contains a lot of water and air, which is good for plants. Plants get what they need from the soil.

15. Changes to the Land Weathering is the way rocks are broken down into smaller pieces. Weathering is always changing the surface of Earth. The Earth’s crust is rock. But most of the land around you is covered with soil, sand, or pebbles. That’s because of weathering. Very slowly, weathering acts on rocks. Bit by bit the rocks are worn away. After thousands of years, the solid rocks are broken down into soil. Weathering is caused by more than the wind. Water also causes weathering. Even plants help break apart rocks on the surface of the Earth. Water causes weathering when it freezes. Most things take up less space when they freeze. But frozen water takes up more space. Water flows into cracks and holes in rock. As the temperature drops, the water freezes. Since the ice takes up more space, it pushes against the rock around it. The force of the ice widens the cracks and breaks the rock into pieces. Water also causes weathering when it is not frozen. The movement of water wears rock away. Also, rivers pick up rocks and bounce them around. This wears the rocks down. Plants cause weathering, too. Roots grow into cracks in rock. As the roots get bigger, they split the rock.

16. BREAK IT DOWN! Erosion and Weathering • Erosion is the process that breaks things down. As far as we're concerned, erosion is the breakdown of the continents and the land around you. Through the process of erosion, boulders can become sand. Mountains are rained on and become hills. The pieces of the mountain become smaller pieces and go down the sides of hills. Weathering and erosion always happen in a downhill direction. Of course, weathering and erosion take many years. • Erosion is an easy idea to understand. If you see a rock, pull it out of a mountain. Then throw it down on the ground. You are now a part of the erosion of that mountain. You have taken a big object (a mountain) and started to make little objects out of it (a rock). When that rock hit the ground, it could have cracked and made some tiny pieces of rock (sand). Erosion is just that easy. When it rains, the same process happens. Rocks are washed down a mountain or down a stream. Soils are washed away. The ocean beats against a cliff and breaks it apart. Water Erosion • Water is the most common way erosion occurs. Raindrops (especially in dry environments) create splash erosion that moves tiny particles of soil. Water collecting on the surface of the soil collects as it moves toward streams and creates sheet erosion. In streams, water is very powerful. The faster water moves in streams the larger objects it can pick up and transport, or move. • Wind Erosion • Wind also causes erosion of the soil. It occurs almost always in deserts. This type of erosion causes the formation of sand dunes. The power of the wind erodes rock and sand. • Ice Erosion • Erosion caused by ice is actually a bit greater than the power of water but since water is much more common, it is responsible for a greater amount of erosion on the earth's surface. • Glaciers are the main form of ice erosion. One way glaciers erode the land is by water entering cracks under the glacier, freezing, and breaking off pieces of rock that are then transported by the glacier. Another way ice erodes the land is when it cuts into the rock under the glacier, scooping rock up like a bulldozer and smoothing and polishing the rock surface. • Wave Erosion • Waves in oceans and other large bodies of water produce coastal erosion. The power of ocean waves is enormous. Large storm waves can produce 2000 pounds of pressure per square foot. The pure energy of waves along with the chemical content of the water is what erodes the rock of the coastline. Erosion of sand is much easier for the waves and sometimes, there's an annual cycle where sand is removed from a beach during one season, only to be returned by waves in another.

17. Animal Facts • Mammal- animals that have fur or hair, use lungs to breathe, give birth to live young, and feed on milk made from their mother's body. There are many types of mammals. Most of them have the above 4 traits. Some also have other traits, such as trunks, fins, wings, or pouches. • Birds- animals that have feathers, two legs, and wings. They have lungs for breathing and bear young that hatch from eggs. There are many types of birds. Birds are grouped together because of traits they share. The most common traits used for grouping birds are beak shape and foot shape. The shape of a bird's beak can be used to tell what the bird eats. The shape of a bird's feet can be used to tell where it lives. • Amphibians- animals that begin life in water and move onto land as adults, they lay eggs, and have moist skin. Gills- body parts that take in oxygen from the water. • Fish- animals that live their whole live in water and breathe with gills. Most fish lay eggs, but some fish give birth to live young. Scales- thin, small, flat plates that help protect the fish. • Reptiles- covered with scales, lay eggs on land, and breathe with lungs. (Most live in warm, wet tropical rain forests or in hot, dry deserts.) • Three groups of Reptiles- lizards & snakes, alligators & crocodiles, tortoises & turtles.

18. Animal Behavior & Extinction Vocabulary • 1. Instincts- behaviors an animal knows how to do. • 2. Hibernate- to enter a deep sleep in which life activities slow down. • 3. Migrate- to travel as a group from one place to live to another place and back again. • 4. Mimicry- an animal's imitation of another animal or of an object in order to avoid predators. • 5. Camouflage- a natural disguise some animals have to help them blend in with their surroundings. • 6. Extinct- describes a species that is gone forever because all of its kind have died. • 7. Causes of extinction- habitat loss, new predators, over hunting • 8. Species- a name that identifies a specific kind of organism. • 9. Endangered- in danger of becoming extinct. • 10. Threatened- On the way to becoming endangered or extinct. • 11. Fossil- something that has lasted from a living thing that died long ago.

19. plain plateau mountain landform volcano earthquake weathering harbor peninsula • _____________ breaks down rock into smaller pieces. • A _________________ is an opening in Earth's surface from which lava flows. • _____________is land that has water around most of it. Think of Florida. • A place on Earth's surface that is much higher than the land around it is a _______________________. It is the highest kind of land. • _____________ is the area of water where ships can dock safely near land. • A __________________ is any feature on the Earth's surface. • 7. A flat landform on the Earth's surface is called a _____________________. • 8. A __________________ is a large area of high, flat land with steep sides. • 9. ___________________ is the shaking of Earth's surface caused by movement • of the crust where it meets the mantle. • Name the 4 things that soil contains. • _____________________________ • _____________________________ • _____________________________ • _____________________________

20. plain plateau mountain landform • weathering harbor peninsula • * Use the terms above to complete the sentences. • _____________ is the area of water where ships can dock safely near land. • _____________ breaks down rock into smaller pieces. • _____________is land that has water around most of it. Think of Florida. • A __________________ is a large area of high, flat land with steep sides. • A place on Earth's surface that is much higher than the land around it is a _______________________. It is the highest kind of land. • A __________________ is any feature on the Earth's surface. • A flat landform on the Earth's surface _____________________ • soil humus topsoil bedrock clay loam conservation • * Use the terms above to complete the sentences. • Rich soil with lots of humus is _________________________. • ____________________ is a type of soil with very small grains and small spaces between them. • ______________________ is the layer of bits of rocks and humus found on Earth's crust. • ________________ means saving resources by using them carefully. • The top layer of soil is_____________________. • The decayed remains of dead plants and animals in soil is________________. • The layer of rock beneath the soil is ________________________.`

21. Georgia • Georgia is a very interesting state. It has different types of habitats, and different animals and plants. Atlanta is the capital of Georgia. The state’s leader, called a governor, lives and works in the state’s capital city. Georgia has four different regions, or areas. Each region also has different types of plants and animals. • North Georgia is the mountain region. These mountains are part of the Appalachian Mountain Range. Many black bear live in the mountains. Animals that live in the mountains must be able to adapt to the living conditions. Some adaptations are hibernating, migrating and camouflage. • South of the mountains is the Piedmont region, which means foothills of the mountains. The piedmont region is where most of the cities in Georgia are located and where we live. The main crops in this area are wheat and rye. There are also many pine trees in this region. • South Georgia is made up of plains, which is low flat land. Many crops are grown in the plains region of Georgia, such as peanuts, cotton peaches and watermelons. Peanuts prefer sandy soil, so they grow best in the plains region. Different crops grow better in different types of soil. • Georgia also has a swamp in the plains region called the Okefenokee Swamp. The swamp has a lot of unique wildlife, like alligators, heron, black bears and snakes. Swamp plants include water lilies, cypress trees, and peat formed from fernlike plants that have decayed. Plants that live here are adapted to live in a wet environment. • Georgia borders the Atlantic Ocean. The part of the state that borders the ocean is called the Coastal Plain Region. In this area, palm trees can live and grow well. In the ocean, Georgia has a lot of wildlife. There are dolphins, sharks, sea turtles, and other ocean animals. • Since each region has a different climate and landforms some plants and animals can only live in one region. Other animals, like deer, squirrels, rabbits, and raccoons can live in all areas of the state. Birds also live in all areas, but they have adaptations for their habitat like their feet and beaks.

22. Pollution and Conservation (more to come soon)