Guide to Preparing for the Science Assessment

Transcription

1 Metropolitan Community College Guide to Preparing for the Science Assessment In today's highly technical world, Metropolitan Community College believes that all students, regardless of major, should leave college with the basic skills needed to read and understand scientific information, including that normally found in newspapers. This assessment requires you to understand, interpret, or apply information that is provided on the assessment itself, or that you have learned through life experience. The information on the assessment may be in the form of a paragraph (i.e., text only), a formula or equation, a chart, a table, a graph, a map, or a figure. Knowledge, skills, and abilities evaluated include: Knowing some basic scientific concepts and principles Knowing the basic measurement systems used throughout the world Ability to carefully read, understand, interpret, and apply information presented in paragraph form, in tables, or in line, bar, or pie graphs Ability to identify implications and draw conclusions based upon the information given in the problem Ability to calculate simple mathematical ratios and probabilities Skill in using ideas in a context different from the one in which they were originally given (application, problem solving) The science assessment does not appraise your knowledge of any specific science nor does it depend upon an extensive science background. Its content should be a reasonable task for a high school graduate. The assessment contains 20 questions; you need to get 11 correct to be placed in a 100 level science. How to prepare for the science assessment: Preparation for the assessment should not involve a great deal of memorization. Use this handout for sample questions; if necessary, review basic scientific principles using the software in the Learning Centers. More importantly, you should practice reading, understanding, and solving scientific problems. In this handout you will find: Sample test questions with answers and explanations A list of Metro Community College resources for science students THE FOLLOWING PAGES CONTAIN SAMPLE QUESTIONS OF THE TYPE FOUND IN EACH OF THE FOUR MAJOR AREAS OF THE TEST Page 1

2 MEASUREMENT The metric system is used extensively in business, engineering, and the sciences throughout the worlds. Although it is not the system commonly used by Americans, it is used in almost all other nations. It is a simple, logical system which is based on units in multiples of ten. Ability to use the system and to make general conversions between it and the American system are important in all areas of study. You have to be familiar with basic units in the English and Metric measurement systems and be able to apply them to your everyday life experience. The chart below shows basic length, weight and capacity units in both systems: LENGTH WEIGHT CAPACITY English English English inch ounce cup foot pound pint yard ton quart mile gallon Metric Metric Metric millimeter milligram milliliter centimeter gram liter meter kilogram kilometer With Metric system, it helps if you can relate the metric prefixes to the decimal system: For example: 1 kilometer = 1000 meters 1 milliliter = 1/1000 (or 0.001) liters Also, there are some temperatures to memorize: Fahrenheit Celsius Freezing 32 o F 0 o C Boiling 212 o F 100 o C Normal body 98.6 o F 37 o C You have to be able to approximate English measurement standards with the closest Metric measurement standards and determine appropriate units to measure length, weight or capacity of some common items. To help you with this, we recommend you take lesson Appropriate Units of Measure from the SkillsBank (Basic Math > Measurement and Geometry > Appropriate Units of Measure). You can also take the lesson Measurement (Science 1 > Physical Science > Measurement). SkillsBank software is installed at all three main Learning Centers. Page 2

3 SCIENCE CONCEPTS It is not possible to summarize or review all the basic, essential concepts of the various fields of investigation called "the sciences". The ability to understand some of the concepts and vocabulary of science normally found in newspaper and magazine stories is adequate for success on this assessment. Examples 1. We inhale air as a source of a gas that allows our normal body processes to continue. What is this gas? A. Nitrogen B. Oxygen C. Carbon dioxide D. Ozone 2. What statement below does NOT describe a physical property? A. Oil is insoluble in water. B. Water boils at 100 o C. C. Iron rusts in a damp environment. D. Diamonds are capable of cutting glass. 3. Which of the following is a chemical change? A. Dynamite explodes B. Vinegar and oil separate into two layers C. Sugar crystals are grinded into powder D. Salt dissolves in water. 4. A helium balloon floats because the helium in the balloon A. Is compressed B. Has a higher density than the air C. Has a lower density than the air B. None of the above is applicable. MATHEMATICAL RELATIONSHIPS The accomplishments of science, as well as other areas of study, depend upon gathering and analyzing information. Dealing with numbers and representing them in understandable ways is necessary in all areas of life. Often graphing and graph interpretation is involved. Examples 1. Find the next number in the following sequence: 2, 5, 10, 17, 26,? Page 3

4 A. 38 B. 37 C. 44 D Density relates the mass of a substance to its volume through the formula: m d =. v What is the density of a 75 g block of wood (rectangular solid) measuring 12 cm x 8 cm x 9 cm? (Hint: find the volume of wood first) A. 864 g/cm 3 B g/cm 3 C g/cm 3 D. 96 g/cm Which title below best fits the following graph? Temperature 0 Distances A. Variation in temperature while traveling from Omaha to Des Moines on December 1st. B. Variation in temperature while traveling from Des Moines to Omaha on December 1st. C. Variation in temperature while traveling from Minneapolis to Houston on December 1st. D. Variation in temperature while traveling from Houston to Minneapolis on December 1st. 4. Biologists let down small nets in a different spots around the lake, catching, tagging and releasing 96 fish. A week later, after the tagged fish have had a chance to mix with the general population, the biologists come back and let down their nets again. They catch 72 fish, of which 4 are tagged. Assuming that the catch was representative, how many fish live in the lake? A. 96 B C. 168 D A number from 1 to 11 is chosen at random. What is a probability of choosing an odd number? A. 1 in 11 B. 5 in 11 C. 6 in 11 D. None of the above. Page 4

5 6. Line Graph Questions 6.1. This graph shows the temperatures during the period of a A. Week B. Month C. Year 6.2. The temperatures in the beginning of the week were rising or falling? A. Rising B. Falling 6.3. There was the least amount of change between days A. 6 and 7 B. 5 and 6 C. 1 and If freezing is 32 degrees, which day was above freezing? A. Day 1 B. Day 2 C. Day When was the greatest drop in temperatures between? A. Days 1 and 2 B. Days 3 and 4 C. Days 4 and 5 Page 5

6 We recommend you review lessons Ratio and Proportion (Mathematics > Unit 5: Ratios, Proportions and Probability) from the GED Interactive software and Probability lesson from the SkillsBank software (Intermediate Algebra > Statistics and Probability > Probability). Also, to better understand graphs, you can review lessons Bar Graphs, Linear graphs and Circle Graphs from SkillsBank (Intermediate Math > Statistics and Probability). Both the GED Interactive and SkillsBank programs are available at the three main Learning Centers. PROBLEM SOLVING The method called science is basically an organized, common sense search for relationships. A scientist may ask: "Why did this observation happen? What is the connection between these two events?" Scientific problem solving establishes cause and effect relationships, identifying the reason why experimental results occurred, and reducing the possibility that unknown factors are influencing results. Today the scientific method is used in many areas. One needs to have some sense of how this method works in order to understand claims made by many scientists, businesses and organizations. Examples 1. You suspect that your poor tomato crop is due to either poor soil or the wrong variety of seed for this area. To determine which one of these is the single problem, which change would be appropriate next year? A. Try a different variety, move them to a different site, and add fertilizer. B. Add fertilizer to the same soil, using the same variety. C. Add fertilizer to the same soil and plant a different variety D. Do not add fertilizer, but try a different variety in a different site. 2. When a solution is made from water and some other substance such as salt or sugar, this solution will freeze at a lower temperature than that of water alone, and will boil at a higher temperature than water does. Which of the following best explains why salting prevents roads from becoming icy? A. The salt causes the moisture to evaporate. B. The vapor pressure of the salt and snow solution increases. C. A solution of salt and water has a lower freezing point than that of water alone. D. A solution of salt and water has a higher freezing point than that of water alone. 3. Barometric pressure is a measure of the pressure of the Earth s atmosphere on the Earth s surface at a given location. A decrease in barometric pressure signals the change to some form of precipitation, such as rain or snow. Which of the following words best describes the barometric pressure before a hurricane, which is a tropical storm accompanied by rain, thunder, and lighting? A. steady B. high Page 6

7 C. increasing D. falling 4. Using information from the question 3 and the pressure readings below, select the day on which some form of precipitation would most likely occur: Day Monday Tuesday Wednesday Thursday Friday Pressure 30.6in 29.5in 29.7in 29.9in 30.0in A. Monday B. Tuesday C. Wednesday D. Thursday E. Friday To better understand scientific approach to problems, we recommend you review the following units/lessons from the Science area of GED Interactive software: Unit 1. Understanding Ideas in Science: Lessons 1, 2 and 4 Unit 3. Analyzing Ideas in Science: Lessons 1, 2 and 3 This software is installed at all three main Learning Centers. Answers and Explanations are found on pages 8 & 9. Page 7

8 Answers and Explanations: SCIENCE CONCEPTS: 1. B We extract oxygen from the air we inhale, and we exhale carbon dioxide. Nitrogen gas is not used in body processes, and ozone is poisonous. 2. C Physical properties can be observed or measured without changing the composition of matter. They include: appearance, texture, color, odor, melting point, boiling point, density, solubility, and many others. If iron rusts, a new compound, rust, is formed. Rust is an iron oxide with different properties than iron metal. Therefore, this process describes a chemical, not physical property. 3. A In a chemical change, there is a chemical reaction; as a result, a new substance is formed, and energy is either given off or absorbed. That s exactly what happens when dynamite explodes. In B, C and D no new substances are formed, therefore they represent physical, not chemical, changes. 4. C If you have a balloon full of helium, it will float high, because helium has a lower density than air does. Things like rocks, on the other hand, have higher densities than air, so they'll just sit on the ground. MATHEMATICAL RELATIONSHIPS: 1. B in this sequence, each term is 1 more than a square, i.e. 2 = , 5 = , 10 = , 17 = , 26 = The next term will be = B First, find the volume of wood: because its shape is rectangular solid, multiply all three dimensions: 12cm x 8cm x 9cm = 864cm 3. Next, find the density using the given formula (round the answer): 75g 864cm 3 = 0.087g/cm C On December 1st we could reasonably predict warmer temperatures in Houston, Texas than in Minneapolis, Minnesota. While traveling from north to south, we would surely notice Page 8

9 the temperature rising. The graph represents that in the line increasing both on the distance and temperature scale. While traveling east west or west east as we would in traveling from Omaha to Des Moines, we would probably not encounter a rise in temperature. 4. C To solve this problem, write a ratio (X will represent the total number of fish in the lake): 96 taggedfish Xfish 4 taggedfish = ; X = (96 72)/4; X = 1728 fish. 72 fish 5. C Probability is a ratio of a number of favorable outcomes to a total number of possible outcomes. There are 11 numbers from 1 to 11 (they are possible outcomes), 6 of which are odd numbers (favorable outcomes); that gives us the ratio 6 in A The graph shows average daily temperature for January 1 7, which is a period of one week. 6.2 A 6.3 B 6.4 C 6.5 C PROBLEM SOLVING: 1. B There are two suspected reasons for a poor crop poor soil or wrong seed but any useful test can only be done on one of these at a time. Otherwise we will not know which change in tomato growing is responsible for any improvement that might appear in the crop. In answers A, C and D there are two or three variables different site, fertilizer and a different variety of seed being tested at the same time. Anyone of these variables could give different results, but we wouldn't know which one. 2. C A mix of salt and water has lower freezing point, and that slows the rate at which melted water turns to ice. Therefore, less ice would form on the road surface, and it will be less slippery and safer to drive on. 3. D A hurricane is usually accompanied by a large amount of rain. Falling (decreasing) barometric pressure usually indicates precipitation such as rain. 4. B A decrease in barometric pressure signals the change to some form of precipitation. The only day that shows decreasing barometric pressure is Tuesday. Page 9