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									               Science: Reading Support and Homework - Model Answers

                                   Chapter 7: The Rock Cycle

                            Lesson 1: What are the Types of Rocks?
1. The hardened sugar is similar to an igneous rock. A real igneous rock would have taken much
   longer to form. An igneous rock is made of minerals, not sugar.
2. A -D - C - B
3. Main Idea: It forms when melted rock cools and hardens
   Details: Magma is deep inside Earth. There, temperatures are so hot that rock is liquid. When
   magma reaches Earth’s surface, it cools and becomes hard.
4. A) Igneous              B) metamorphic
5. The layers are pressed together. Water that contains minerals moves through the pieces of
   rocks that are being pressed together. This causes the pieces of rock to stick together.
   Sedimentary rock is formed.


                               Lesson 2: What is the Rock Cycle?
1. The better plan would be the second one, because it is important to record where the rocks
   were found and to sort them by more than just size. Size is not a type of rock.
2. Answers will vary but should reflect the correct use of rock cycle.
3. 2 - 5 - 1- 4 - 3
4. A) erosion breaks down rocks                     B) heat and pressure change rock
5. Igneous rocks form when melted rock hardens; making it a solid type of rock. A sedimentary
   rock forms when layers of sediment are squeezed together, making a layered rock. Solid is
   harder to break than layers; therefore, the igneous rock would be harder to break than the
   sedimentary rock.


                     Lesson 3: How Do Weathering and Erosion Affect Rocks?
1. The force of the ocean waves pounding on the shells of ocean animals, and larger ocean animals
   eating smaller shell animals, cracking their shells as they eat, are ways the shells might have
   been broken into pieces.
2. Weathering – Erosion
3. Cause: A seed drops into a crack of a rock.
   Effect: a plant grown in the crack breaking it.
   Cause: water gets into the crack and freezes it.
   Effect: The frozen water expands and breaks the rock.
4. A) water or waves                 B) Acid         C) Expands
5. As the river overflows, it takes sediment such as dirt and rocks to other places. The overflowing
   water deposits the sediment elsewhere.
                               Chapter 8: Changes to Earth’s Surface

                       Lesson 2: What Causes Changes to Earth’s Landforms?
1. the crust - the core - the mantle
2. C - A - B - D
3. Cause: Earth’s crust is broken into plates.
   Effects: plates move towards each other.
   rocks from two different plates stick together
   Great pressure can build up
   rocks break apart suddenly
   waves of energy
4. A) mountain chain forms
   B) volcanoes can form
   C) Large cracks form and magma oozes up to form new crust
5. The volcano may erupt. Moreover, the construction of steady buildings is probably difficult since
   the land may be hard to dig because it may be mostly made up of volcanic rock..



                              Chapter 15: Making and Using Electricity

                                   Lesson 1: What is Electricity?
1. Trial                       Number of Batteries              Bulb Brightness


2. C – E – A – D – B – F
3. 2 – 5 – 1 – 3 – 4

4.
                       wire


      battery or
                                      bulb
        outlet




                               more
             switch
                               wire



5. This strand of light is most likely a series circuit. One bulb breaks, which stops the flow of charges
    to the other bulbs.
                    Lesson 2: How are Electricity and Magnetism Related?
1. The magnet farther away was larger or stronger.
2. Magnetic field
   Electro magnet
   Electric motor
3. Alike: The S and N poles are where a magnet exerts the strongest force. Different: Opposite
   poles attract. Like poles repel.
4. A) attract        B) poles       C) electric current
5. Since magnets do not attract plastic, the plastic car must have had some parts inside, such as
   screws, which were attracted by the magnet.


                       Lesson 4: How Do People Use Energy Resources?
1. At Home: Oven, Dishwasher, Hair dryer
   At School: Lights, School bell, Computer
   In Our Neighborhood: Traffic lights, Car wash, Street lights
2. Answers will vary but should reflect the correct use of terms.
3. Main Idea: Mercy practices ways to save energy. Details: Mercy replaced all the bulbs with
   energy efficient bulbs. She turns off the television when no one is watching it.
4. A) home          B) school        C) business or industry
   D) fuel          E) battery
5. The Smith family probably lives in an area where the winters are not very cold and the summers
   are very hot. They do not need to use a lot of energy during the winter to warm their home. The
   Smith family uses more energy during the summer to cool their home.

								
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