2 nd Term Final. Revision Sheet. Students Name: Subject: Science. Teacher Signature

Transcription

1 2 nd Term Final Revision Sheet Students Name: Grade: 8 A/B Subject: Science Teacher Signature

2 Grade 8 2nd Term Final Revision Sheet Science True/False Indicate whether the statement is true or false. 1. Electromagnetic waves travel through a medium by radiation. 2. A convex mirror curves outward like the back of a spoon. 3. Scattering occurs when certain wavelengths of light are reflected by particles, causing the light to spread out in all directions. 4. A material that allows light to pass through it completely is transparent. 5. Laser light is more intense than other types of light because it comes from a very small range of wavelengths in the visible spectrum. Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Which of the following statements best explains the relationship between eyes and depth perception? A. Having two eyes is not important; depth perception comes from our left eye only. B. Having two eyes is not important; our brains need information from only one eye (left or right) to form a perception of depth. C. Each eye sees objects slightly differently because each eye is in a different location. The images are combined in the brain to form our perception of depth. D. One eye sees objects at a close distance, and the other eye sees objects located far away. The images are combined in the brain to form our perception of depth. 2. After noticing changes in your vision, you take a trip to the eye doctor. She tells you that to improve your vision, she needs to perform surgery to slightly flatten the cornea. What is wrong with your eyes? A. They are farsighted. B. They are nearsighted. C. The retina is not functioning correctly. D. They cannot see objects clearly up close. 3. Which of the following is a characteristic of farsighted eyes? A. cannot see clearly at any distance B. can see things up close most clearly C. cannot see things clearly at a distance D. can see things most clearly at a distance 4. The diagram below shows the eye, with several features labeled. Which part of the eye controls how much light enters the eye? A. A B. B C. C D. D 5. The diagram below shows the eye, with several features labeled.

3 In which part of the eye would you find specialized cells called rods and cones? A. A B. B C. C D. D 6. The table below shows characteristics of vision problems and explains how these problems can be solved. Some of the information is missing. Symptoms and solutions Nearsightedness Farsightedness Symptoms trouble seeing at a distance can see objects up close trouble seeing up close can see objects at a distance Corrective Lens Solution? flatten the cornea Surgery Solution converging lens? Which of the following best completes the table? A. a corrective lens solution for nearsightedness: contact lens; a surgery solution for farsightedness: enlarge the pupil B. a corrective lens solution for nearsightedness: contact lens; a surgery solution for farsightedness: increase the curve of the cornea C. a corrective lens solution for nearsightedness: diverging lens; a surgery solution for farsightedness: enlarge the pupil D. a corrective lens solution for nearsightedness: diverging lens; a surgery solution for farsightedness: increase the curve of the cornea 7. As you walk outside, you notice a rainbow, full of many different colors. Which part of your eye helps you distinguish the different colors? A. pupil B. cornea C. rod cells D. cone cells 8. You notice that your eyes are starting to change, and you re having trouble seeing things clearly up close. What could be wrong with your eyes, and what would be a possible way to correct the problem? A. farsighted; diverging lens B. farsighted; converging lens C. nearsighted; diverging lens D. nearsighted; converging lens 9. What vision problem can be corrected by flattening the cornea? A. blindness B. farsightedness C. nearsightedness D. color vision deficiency 10. Which statement best explains why most people can see colors? A. The eyes and brain can see all wavelengths in the electromagnetic spectrum. B. The eyes and brain rely on all of the radiation from the sun to see colors. C. The eyes and brain interpret different wavelengths of visible light as different colors. D. The eyes and brain see light waves only when they travel through a medium. 11. Which of the choices below is another term for the transfer of energy as electromagnetic waves? A. medium B. magnetic field C. electromagnetic radiation D. wavelength and amplitude 12. The diagram below shows a wave. The features of the wave are labeled A, B, C, and D.

4 Which label identifies the wavelength? A. A B. B C. C D. D 13. The visible part of the electromagnetic spectrum consists of the colors that we see in a rainbow. Different colors correspond to different wavelengths of light. Which color of visible light has the shortest wavelength? A. red B. green C. violet D. yellow 14. Great amounts of electromagnetic energy from our sun and other bodies in space travel through space. Which is a logical conclusion about these electromagnetic waves? A. Their energy must be very low. B. Their frequency must be very low. C. Their wavelengths must be very short. D. These waves can travel without a medium. 15. The energy generated by the sun travels to Earth as electromagnetic waves of varying lengths. Which statement describes an electromagnetic wave with a long wavelength? A. It has a high frequency and low energy. B. It has a high frequency and high energy. C. It has a low frequency and can travel through a vacuum. D. It has a low frequency and needs a medium to travel through. 16. Our eyes detect light that lies only within a small region of the electromagnetic spectrum. This region is called visible light. Which of these statements describes the visible spectrum of light as seen by the human eye? A. The lowest frequency appears green, and the highest frequency appears red. B. The lowest frequency appears red, and the highest frequency appears violet. C. The lowest frequency appears blue, and the highest frequency appears orange. D. The lowest frequency appears yellow, and the highest frequency appears green. 17. The figure below shows the regions of the electromagnetic spectrum.

5 Which of these statements is true? A. X-rays are shorter than visible light waves. B. Ultraviolet waves are longer than radio waves. C. Visible light waves are longer than microwaves. D. Infrared waves are shorter than ultraviolet waves. 18. The table below lists electromagnetic waves. A B C D Low frequency Radio waves Gamma rays Laser light Visible light Microwaves X rays Visible light X rays Infrared waves Ultraviolet light Ultraviolet light Ultraviolet light Visible light Visible light X rays Radio waves High Frequency Ultraviolet light Infrared light Gamma rays Microwaves Which column correctly lists from lowest to highest frequencies? A. Column A B. Column B C. Column C D. Column D 19. Light rays enter a translucent material. Which description best describes what happens to the light rays? A. The rays bounce straight back. B. The rays move straight through. C. The rays spread out in all directions. D. The rays move through, but in one new direction. 20. A student wakes up one morning and sees that it is foggy outside. Which response below best describes what is happening to the light outside? A. The fog scatters the light. B. No light is transmitted at all. C. The light bounces off the fog. D. The light travels clearly through the fog. 21. The diagram below shows four thin beams of light interacting with a material.

6 Which beam best shows absorption? A. 1 B. 2 C. 3 D Which color will a red rose appear to be if only a blue light reached it? A. red B. white C. black D. purple 23. In which of these situations would light slow down? A. from glass to air B. from ice to water C. from plastic to air D. from a vacuum to air 24. Which of these materials best scatters the light that strikes it? A. pure water B. shiny mirror C. frosted glass D. eyeglass lens 25. Three students shine lights onto the same spot on a white table. One student shines a blue light. Another student shines a red light. The third student shines a green light. What color will the spot appear to be? A. black B. orange C. white D. yellow 26. The diagram below shows four light rays interacting with a material. The material is transparent to which light ray? A. ray 1 B. ray 2 C. ray 3 D. ray As you are shopping in your favorite store, you look up and notice a convex mirror in the corner. What type of mirror is this and what is most likely its purpose? A. It s a converging mirror and it s used to magnify light in the store. B. It s a diverging mirror and it s used to show a large area of the store. C. It s a diverging mirror and it s used to produce a bright beam of light. D. It s a converging mirror and it s used to show a large area of the store. 28. A student has noticed that she can t see objects clearly when they are far away. An eye doctor diagnoses her as being nearsighted. What type of lens could help the student correct her vision problem? A. flat lens B. convex lens

7 C. diverging lens D. converging lens 29. A beam of light is placed at the focal point in front of a converging mirror. What will happen when the beam shines toward the mirror? A. The beam of light will reflect back to the focal point. B. The beam of light will reflect off the mirror and then diverge. C. The beam of light will reflect off the mirror and then form a parallel beam. D. Converging mirrors do not have focal points in front of the mirror; the focal point is behind the mirror. 30. Which of the following statements about reflected images is true? A. Reflected images are always virtual images. B. Reflected images can vary in many ways from the actual object. C. Reflected images always look slightly bigger than the actual object. D. Reflected images always look exactly like the object they are reflecting. 31. An object is placed beyond the focal point of a concave mirror (position 1). The object then moves closer to the mirror, so that the object is closer to the mirror than the focal point (position 2). Which response below best describes the types of images you will see at each position of the object? A. 1: real image; 2: real image B. 1: real image; 2: virtual image C. 1: virtual image; 2: real image D. 1: virtual image; 2: virtual image 32. How is the shape of a diverging mirror different from the shape of a diverging lens? A. There is no difference; both are always convex. B. There is no difference; both are always concave. C. A diverging mirror is convex and a diverging lens is usually concave. D. A diverging mirror is concave and a diverging lens is usually convex. 33. The diagram below shows how two different viewers would see the same object in a mirror. Why does the image, shown at point X, appear to be behind the mirror? A. The image appears to be behind the mirror because the object is behind the mirror. B. The image appears to be behind the mirror because the viewers are behind the mirror. C. The image appears to be behind the mirror because our brains interpret light in straight lines. D. The image appears to be behind the mirror because the rays from the image come from behind the mirror. 34. Which of the following properties is true of a converging lens? A. is often concave on both sides B. focuses a parallel beam to a point C. causes a parallel beam to spread out D. is thinner at the center than at the edge

8 35. An object is placed several feet in front of a diverging mirror.the object is then moved four times, each time getting closer and closer to the mirror. What will happen to the image size and location as the object moves closer to the mirror? A. The image size and location will be unchanged. B. The image size will increase, and the image location will move closer to the mirror. C. The image size will appear unchanged, and the image location will move closer to the mirror. D. The image size will decrease, and the image location will move farther away from the mirror. 36. What is one of the earliest ways that ancient peoples produced light? A. candles B. light emitting diodes C. fluorescent bulbs D. incandescent bulbs 37. How do incandescent bulbs produce light? A. Light of one color is concentrated and amplified. B. Material inside the bulb becomes hot and produces light. C. Gases within the bulb are energized by an electric current and interact with a phosphor coating. D. Solid materials within the bulb are energized by an electric current. 38. The following image shows one type of light technology. What technology is shown and how is it useful in the medical field? A. It s an incandescent light; it can keep patients warm during surgery. B. It s a laser; it helps doctors stay in touch with other doctors via cell phones. C. It s a light-emitting diode; it can display information about patients on a screen. D. It s a fiber optic cable; it can illuminate otherwise unreachable parts of the human body. 39. Some cameras record motion data. What is the correct term for the sequence of images recorded in this way? A. book B. video C. photo D. computer 40. After noticing you have trouble seeing things at a distance, your eye doctor prescribes glasses for you to wear. How is this a type of light technology? A. Eyeglasses can store information. B. Eyeglasses can transfer information. C. Eyeglasses can help humans control light. D. Eyeglasses can emit light to help us see better. 41. Which of the following is an example of a technology that uses light to physically change matter? A. an oven that captures sunlight to cook food B. a microscope that focuses light to magnify an image C. optical fibers that transmit information stored as light D. corrective lenses that redirect light as it enters the eyes of a nearsighted person 42. What type of light technology emits light by energizing solid particles with an electric current?

9 A. LED B. laser C. incandescent D. No type of light is produced by energized solid particles. 43. Which statement accurately compares fluorescent lightbulbs and neon lightbulbs? A. Fluorescent lightbulbs and neon lightbulbs are different names for the same technology. B. Fluorescent lightbulbs and neon lightbulbs both emit electromagnetic radiation that must pass through special chemicals to become visible. C. Fluorescent bulbs emit light when they become hot enough to produce visible radiation; neon bulbs emit light when energized by an electric current. D. When energized by an electric current, the gases in fluorescent bulbs emit ultraviolet light; when energized by an electric current, the gases in neon bulbs emit visible light. 44. Which of the following light technologies is known for losing very little light during transmission? A. LED lights B. laser lights C. fiber optics D. incandescent bulbs 45. In 2008, Evan B. Forde received a congressional commendation as one of the nation s leading African-American scientists and explorers. He received the award in Jacksonville, Florida, where he works to help increase students interest in mathematics, oceanography, and earth science. In what area has Forde s work had an impact on society? A. education B. astronomy C. engineering D. energy resources 46. Science affects our lives in different ways. What is one way that science has directly affected our health? A. discovery of planets B. vaccine development C. manufacture of efficient fuels D. discovery of the structure of the atom 47. What is one way that science has directly affected our ease of travel? A. discovery of planets B. vaccine development C. development of the airplane D. discovery of the structure of the atom 48. Florida A&M University has an Environmental Sciences Institute. In which area would research at this institute most likely have an impact? A. weather prediction B. new technology products C. development of new medicines D. conservation of natural resources 49. The graph shows the number of a school s male and female athletes. How can the data help the principal increase student participation in athletics?

10 A. She can identify from the data why students like participating in sports. B. She can see why there is a decrease in participation between 2005 and C. She can tell why there were equal numbers of male and female athletes in D. Participation data from the previous year can help her set goals for next year. 50. Which of these scientists would most likely engage in fieldwork to observe organisms? A. chemist B. biologist C. physicist D. mathematician 51. Ricardo was volunteering at a library. The librarian asked him to help clean the research area. Ricardo found the map shown below in a stack of papers. The librarian told Ricardo that some scientists use a map such as this one. Which type of scientist most likely uses this map? A. chemist B. biologist C. geologist D. physicist 52. Examine the map shown in the figure below. Some of the information used to create the map was most likely gathered during what type of investigations? A. fieldwork by geologist working in the area B. biologists observing the animals in the area C. laboratory experiments done far away from the area D. surveys of people living in the area 53. Which of these events might lead to the modification of a scientific idea? A. A scientist uses a computer to teach a scientific concept to students.

11 B. Two scientists doing the same experiment in different parts of the world under the same conditions get the same results. C. One scientist finds evidence that she feels doesn t fit a theory. Other scientists agree that her results are valid. D. A scientist performs an experiment and finds out that one of the chemicals used in the experiment was contaminated. 54. The figure below shows a concept related to the kinetic theory of matter, which describes the behavior of gases based on the motion of the particles. How would the kinetic theory explain what is happening in the above example? A. The balloon gets bigger as the temperature of the gas inside it decreases, because the gas particles move faster and get farther apart. B. The balloon gets smaller as the temperature of the gas inside it decreases, because the gas particles begin to escape from the balloon. C. The balloon gets bigger as the temperature of the gas inside it increases, because the gas particles move faster and get farther apart. D. The balloon gets smaller as the temperature of the gas inside it increases, because the gas particles move more slowly and get closer together. 55. Which of the following is a scientific law? A. Climate is changing due to human activities. B. Microorganisms are the cause of many illnesses. C. Tectonic plates move because of a flexible layer beneath Earth. D. Any two objects exert a gravitational force of attraction on each other. 56. Kathleen made the diagram below to show how scientific knowledge changes over time. Which word or phrase best describes what scientists would do at the point indicated by the blank? Original idea +? modified idea A. new evidence B. form an opinion C. change the data D. design an experiment 57. Diep did some research about classification for a science report. She learned that until 150 years ago, scientists recognized only two groups of organisms: plants and animals. Now, scientists also recognize several groups of microscopic organisms. How should Diep explain why scientists decided to classify organisms into more groups? A. More types of organisms exist now than before. B. Fewer organisms have gone extinct in recent years. C. Scientists continue to learn more about living organisms. D. Scientists invent new organisms that need to be classified. 58. The below image shows three different models of the atom.

12 Which statement best explains why there are different models of the atom? A. Each model represents a different scientific opinion about an atom s structure. B. The models of the atom changed as different hypotheses were tested and accepted. C. Models of the atom are always proved false. The current model will eventually be replaced by a newer model. D. Thomson s model and Rutherford s model were never accepted by their peers; only the current model is correct. 59. Why might a scientist decide to do a laboratory experiment instead of fieldwork? A. to include a larger number of variables B. to make observations under natural conditions C. to make observations in a controlled environment D. to have a smaller sample size to observe and experiment on 60. Scientific investigations involve many steps and processes. Which characteristics define a laboratory experiment? A. hypothesis, models, and calculations B. test variables, data, and uncontrolled conditions C. data, conclusions, and unregulated environment D. independent and dependent variables, data, and controlled conditions 61. Scientists conduct many types of scientific investigations. Their efforts often include fieldwork, surveys, models, and experiments. Which statement about scientific investigations is true? A. They rarely involve the collection of data under controlled conditions. B. They follow exactly the same steps because there is only one scientific method. C. They include multiple trials to increase the consistency of the data that are collected. D. Their primary focus seldom includes comparing or describing the unregulated world. 62. Adam s hypothesis states that an object s speed constantly changes. Which data requires Adam to form a new hypothesis? A. B.

13 C. D. 63. New experimental data does not support a currently accepted hypothesis. Which course of action should the researcher take? A. Do the experiment until the results support the hypothesis. B. Change the data to fit the hypothesis. C. Form a new hypothesis and plan a new experiment. D. Change the procedure to obtain the desired outcome. 64. There is no single correct way to conduct a scientific investigation. However, there are some techniques that are part of all good investigations. Which of the following is a characteristic of all good scientific investigations? A. keeping accurate records B. working with other scientists C. using expensive scientific equipment D. conducting the investigation in a laboratory 65. A group of scientists wants to determine how members of a community view climate change. Which of the following would best accomplish this goal? A. creating a model of the effects of climate change on an ecosystem B. taking a survey of a group of people about their opinions on climate change C. performing a laboratory experiment to replicate the effects of climate change D. conducting fieldwork to analyze the different gases that contribute to climate change 66. Deandra designs an experiment to test how far a rubber band stretches when objects of different masses are suspended from it. She records her data in a chart. Mass (g) Stretch (cm) Mass (g) Stretch (cm) Which variable is independent? A. Band type B. Stretch C. Time D. Mass 67. Which of the following is an example of a scientific claim? A. Numbers have symbolic meaning beyond their mathematical sense. B. According to data collected over the past hundred years, the global temperature of Earth is rising. C. One can determine the exact location of water underground by feeling the aura of the water with a forked stick. D. The future can be predicted by studying the position of the planets relative to the stars at a given moment. 68. A scientist graphs the mass and volume of three samples, as shown in the graph below.

14 Which personal trait does the scientist need when attempting to analyze data like the information shown here? A. curiosity B. imagination C. logic D. skepticism 69. A student is studying plants that grow in different areas and receive different levels of carbon dioxide from their environments. The student finds that in one area, plants have shown tremendous growth, whereas in another area, plants have shown little to no growth. The student hypothesizes that the different levels of carbon dioxide contributes to the differences noticed in the plants. Which of the following would best test this hypothesis? A. a model that simulates weather and the water cycle in the plant areas B. fieldwork to identify additional plant types in other areas C. a controlled experiment in which the student attempts to control all variables except the carbon dioxide level D. surveys of people on whether the plants they prefer to grow in their homes and gardens 70. Which of the following best supports a scientific explanation? A. personal bias and the opinion of the scientist B. an hypothesis formed after initial observations C. the imagination and originality of the hypothesis D. experimental data obtained by using technology to make objective measurements Short Answer 1. Explain what the cornea is and how it interacts with light. What is the role of the retina in vision? 2. How are the frequency and wavelength of electromagnetic waves related? 3. How are the frequency, wavelength, and energy of electromagnetic waves related?

15 4. Name three main shapes that mirrors can have. What is the difference between converging and diverging mirrors? Describe real and virtual images. 5. List three ways that humans can control light, and give an example of each. Predict one way that light technology might benefit humans in the future. 6. Explain how the work of scientists benefits our society as a whole. 7. After the results of an experiment, a scientist decides that a long-held scientific theory must be revised. The scientist modifies the theory and tells other scientists. Predict the scientists reaction, and explain why they might react that way. 8. After the results of one experiment, a scientist decides that a long-held scientific theory must be revised. Describe what must be done first before the scientific theory is changed.

16 9. Using an example, explain the difference between a hypothesis and a prediction. 10. Evaluate the strengths and limits of science in terms of scope. 11. Explain how the work of scientists benefits our society as a whole. Essay 1. Describe the type of vision problems that diverging and converging lenses can fix. Explain how the lenses correct the vision problems, and describe how the lenses can change the way light strikes the retina.

17 2. Give two examples of natural light and two examples of artificial light. How is natural light transmitted? How is artificial light produced? 3. Give two examples of natural light and two examples of artificial light. How is natural light transmitted? How is artificial light produced? 4. If you have a blue backpack, what color would it appear if you look at it through blue glass? What color would the backpack appear if you look at it through red glass? Explain your answer. 5. If you have a red backpack, what color would it appear if you look at it through red glass? What color would the backpack appear if you look at it through blue glass? Explain your answer.

18 6. Explain the difference between a virtual image and a real image. Describe a situation in which you might see each type of image. 7. Give two examples of natural light and two examples of artificial light. How is natural light transmitted? How is artificial light produced?

19 8. Shakira predicts that hot metal objects do not cool at a constant rate. She experiments by heating a metal object and then allows it to cool to room temperature. She measures the temperature of the metal with a thermometer every half hour, and she carefully records her results in her notebook. From her temperature data, she draws the following graph. Based on the graph, was Shakira s prediction supported or not supported? Explain how you know. What could Shakira do to make sure her results are replicable? Shakira learns that the cooling system turned on approximately one hour after the experiment began. Explain how this could have affected the experiment and what Shakira should do to prevent this from happening in the future. 9. Shakira predicts that hot metal objects cool at constant rates. She experiments by heating a metal object with a Bunsen burner and then allowing it to cool to room temperature. She measures the temperature of the metal every half hour, and she carefully records her results in her notebook. From her temperature data, she draws the following graph.

20 What tool should Shakira use to collect quantitative data during her experiment? Based on the graph, was Shakira s prediction supported or not supported? Explain how you know. What could Shakira do to make sure her results are replicable? Shakira learns that the heating and air conditioning system turned on at around one hour after the experiment began. Explain whether this could affect the experiment and what Shakira should do. Other 1. A scientific is a well-supported and widely accepted explanation of a natural occurrence. 2. A(n) is an organized procedure to study something under controlled conditions. 3. Scientists collect and record. 4. A(n) is deliberately changed in a scientific study. 5. The collective body of observations of a natural phenomenon on which scientific explanations are based is called.

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