Scientific Literacy & the Scientific Method

Transcription

1 Scientific Literacy & the Scientific Method What does it mean to be? You ve probably hear that term before, and you might be thinking that literate means the ability to and. But what does it mean to be literate? The thing is, is that for every subject there is different literacies that are connected to that particular subject area. So the meaning of scientific literacy might be described as the ability to read and write in the area of. But more specifically scientific literacy goes beyond that and asks the questions, Is there a different way to in science? Is there a different way to? One area that sets science apart from other disciplines is something called the. The starting place for this method is. Science, in its simplest form, is nothing more than observing the world around us and asking the question Why? or How? Whether you knew it or not, when you first asked a parent or an older sibling Why is the sky blue? you were engaged in. So what do scientists do? They,, and. In order to successfully do that, they follow something called the Scientific Method. 1 P a g e N o t e s

2 Another aspect to being science literate is to know how to properly display data that you have generated through the Scientific Method. We need to be literate in graphing skills to be successful scientists. What are the steps to making a proper graph? 1. Always use a ruler and a pencil to create a graph 2. Provide a title for the graph that accurately describes your data 3. Label your axes with the proper label AND provide the unit of measurement 4. Determine the largest and smallest values for each set of measurements. Knowing these values will allow you to choose an appropriate scale for each axis. Make sure that the scale extends your whole graph paper and spacing is even! 5. Plot your points clearly 6. Connect your points with a ruler that connects each point, OR a smooth curve that passes Activity through each point. A line of best fit may be needed. Using the data tables below, prepare one graph (double line graph) with both sets of data below by following the steps above. After you are finished, answer the following question for each graph: what do you think this graph is showing us? This graph represents data taken from an Indy 500 Car Race: Time (s) Distance (m) This graph represents data taken from a car driving down the highway: Time (s) Distance (m) P a g e N o t e s

3 3 P a g e N o t e s

4 The Process of Scientific Inquiry and are the starting points for learning about the natural world. However, investigating questions in, finding solutions to, and deciding on appropriate courses of in different situations are not simple one-step tasks. Each of these skills is actually a multi-step process called the. Is there only one scientific method?, there are several. Some versions have more while others may have only a few, like the one on the earlier page. However, they all begin with the identification of a or to be answered based on of the world around us and provide an organized system for and an experiment. Let s take a look at specific version of the Scientific Inquiry Model: see next page! 4 P a g e N o t e s

5 The Scientific Method A Process for Scientific Inquiry 5 P a g e N o t e s

6 Doing Science vs. Thinking Science The Scientific Inquiry Model is a great example of how to science. But science isn t always about doing. Doing has a very important place in science but isn t the entire picture. There is also a way to scientifically or to put it another way to THINK like a. While and about science are closely related and in many ways, they have a slightly different approach and can be used at different times. For instance, when you make in everyday life, and generate a, you may want to do an or use the Scientific Method. But at other times, you may not be able to do an experiment, so the scientific method may not always be appropriate or applicable. Does this mean that science is no longer useful?? If we only see science as the Scientific Method we may fall into this trap. But fear not! Science is not just limited to this narrow definition. There is more to science than just the Scientific Method. There is a way to scientifically. While there are many ways to think scientifically we are going to focus on 3 that will lead out discussion. In order to scientifically about something, or be scientifically, we are going to consider the following questions:??? Each of these questions comes with important criteria: 6 P a g e N o t e s

7 Is it Scientific? (Does it play by the rules of Science?) Focuses on and aims to the world Created from ideas (falsifiable) Produces, evidence Leads to ongoing Involves the scientific (peer reviewed) Can it be trusted? Information comes from and sources Accurately describes the views of the scientific Issue is not or made controversial Includes or to available research and more information Can I explain it? Identify the points Use words and FROM THE TEXT! Written in sentences without unnecessary words or Written for the intended - 7 P a g e N o t e s

8 As you can see, these criteria turn almost into a type of in order to things scientifically. If one criterion isn t met it may still be considered scientifically sound but if several criteria are missing the issue or topic becomes highly from a scientific view or way of thinking. Here s the thing this sounds kinda mean and maybe a little bit harsh but science doesn t care what you or how you. Science is concerned with. What we can prove and what we know for sure. It is a way of the world and navigating through the minefield of information that exists all around us. Science seeks to discover the regardless of what you personally. 8 P a g e N o t e s

9 Are Units Important in Science?!!! Units of measurement are the terms that we use to. You probably know that units include things like seconds, kilograms, meters, and so forth. Without standard units of measurement, scientists would have a huge problem understanding what other scientists were saying. After all, if I were to refer to a meter as "the length of my leg" and another scientists were to refer to it as "the length of a Saint Bernard dog", we'd have a lot of trouble when it came to do actual science. To avoid this problem, the SI system of units gives us a that we can agree on. Although there are other systems of measurement, the two most common are the (SI) and the system. In Canada, the official system of measurement is the. Because of Canada s close proximity to the United States, you should be familiar with both systems. Both are used in certain contexts. : the modern version of the metric system; uses the metre as the basic unit of length : the system most commonly used in the United States; the standard unit of measurement for length is the foot o If you look at a ruler marked in imperial units, you will notice that it is usually divided into halves, quarters, eighths, and sixteenths, whereas the SI system uses tenths. Below are listed some common imperial units of length and their relationships. 12 inches (in or ) = 1 foot (ft or ) 36 inches = 1 yard (yd) 3 feet = 1 yard 5280 feet = 1 mile (mi) 1760 yards = 1 mile 9 P a g e N o t e s

10 Importance of Significant Figures, Scientific Notation, Decimals & Rounding 1. SIGNIFICANT FIGURES (SIG FIGS) Significant figures are those digits to express the results of a measurement to the precision with which it was made. No measurement is ever absolutely correct since every measurement is by the or of the instrument used. Ex: if a thermometer is graduated in one degree intervals and the temperature indicated by the mercury column is between 55 C and 56 C, then the temperature can be read precisely only to the nearest degree (55 C or 56 C, whichever is closer). If the graduations are sufficiently spaced, the fractional degrees between 55 C and 56 C can be estimated to the nearest tenth of a degree. If a more precise measurement is required, then a more precise measuring instrument (e.g., a thermometer graduated in one-tenth degree intervals) can be used. This will increase the number of significant figures in the reported measurement. (See Figure 1) Figure 1. A typical Laboratory Thermometer graduated in C. In dealing with measurements and significant figures the following terms must be understood: tells the reproducibility of a particular measurement or how often a particular measurement will repeat itself in a series of measurements. tells how close the measured value is to a known or standard accepted value of the same measurement. Measurements showing a high degree of precision always reflect a high degree of nor does a high degree of mean that a high degree of precision has been obtained. It is quite possible for a single, random measurement to be very accurate as well as to have a series of highly precise measurements be inaccurate. Ideally, high degrees of accuracy and precision are desirable, and they usually occur together, but they are not always obtainable in scientific measurements. 10 P a g e N o t e s

11 Every measuring device has a series of or on it that are used in making a measurement. The precision of any measurement depends on the of the markings. The the interval represented by the marking, the precise the possible measurement. The of a measuring device depends on how the graduations are marked or engraved on the device in reference to some measurements. For most measuring devices used in everyday work, the graduations on them are usually for general use. In the laboratory, it is not always advisable to accept a measuring device as accurate unless the instrument has been calibrated. is the process of the graduations on a measuring device for. 11 P a g e N o t e s

12 Whether the information from a series of measurements is obtained first-hand or second hand through another source, the number of significant figures must be determined in order to keep all the results meaningful. The rules for writing and identifying significant figures are: 12 P a g e N o t e s

13 2. ROUNDING-OFF SIG FIGS NUMBERS When dealing with significant figures, it is often necessary to numbers in order to keep the of calculations. To round-off a number such as to significant figures means to express it as the nearest digit number. Since is between 64.8 and 64.9, but closer to 64.8, then the result of the round-off is A number such as is equally close to 64.8 and In this case and in similar cases, the rule to observe is to to the nearest number which is This rule assumes that in a series of numbers which are to be rounded off, there will be approximately the same number of times that you would have to round-off to the nearest even number as you would have to roundoff. 13 P a g e N o t e s

14 14 P a g e N o t e s

15 3. DECIMALS AND ROUNDING (NOT SIG FIGS) 15 P a g e N o t e s

16 4. SCIENTIFIC NOTATION In chemistry, we frequently have to deal with very or very numbers. For example, one mole of any substance contains approximately particles of that substance. If we consider a substance such as gold, one atom of gold will weigh grams Numbers such as these are to and are even more difficult to work with, especially in calculations where the number may have to be used a few times. To simplify working with these numbers, we use what is known as. In scientific notation we make the assumption that a number such as: AND can be written as the of two numbers: 2.5 and To further simplify this expression, the number can be written in. Thus, this number, in scientific notation becomes: = In proper scientific notation form, the significant figures are written so that the is located (counting from left to right). The power of ten is the indicator of how many the decimal point had to be moved to place it between the first two significant figures. In the first number, the number of particles in a mole, given above, in order to place the decimal point between the first significant figures (the 6 and the 0) the decimal point must be moved spaces from the to the. The number of spaces the decimal point is moved will be expressed as a. In proper scientific notation form, the number of particles in a mole is: particles. 16 P a g e N o t e s

17 In the second number, the number of grams in one atom of gold, the decimal point must be moved spaces form the left to the right. The number of spaces the decimal point was moved will be expressed as a. The weight of one atom of gold, expressed in scientific notation: gram. As you can observe, these two numbers are easier to manage in scientific notation. Some more examples of numbers written in scientific notation are: 4500 = (decimal point moved 3 spaces to the left) = (decimal point moved 5 spaces to the left) = (decimal point moved 3 spaces to the right) Remember, if the decimal point was moved from the in order to place it between the first significant figures, the will be. If the decimal point had to be moved from the, the will be. Another advantage of scientific notation is that, all placeholders are contained in the. This eliminates which are. For example, if the number is rounded off to three significant figures, the result would be Only the zero following the 4 should be significant, the other zeros are place holders. It is not apparent from looking at the number that one of the zeros is significant while the others are not. In scientific notation, this number would be written as 2.40 x 10 4 Thus, the significant is but the placeholders are. 17 P a g e N o t e s

18 18 P a g e N o t e s