Chapter 1 Science Skills

Transcription

1 Chapter 1 Science Skills 1.1 What is Science? How does the process of science start and end? Curiosity provides questions, but scientific results rely on finding answers. In some experiments, observations are qualitative, or. In some experiments, observations are quantitative, or. Some questions - for example, how the universe began- cannot be answered by direct observations and measurements but only by other kinds of evidence. What is the relationship between science and technology? Science - Technology - What are the branches of natural science?

2 - the study of the composition,, properties, and of matter. - the study of matter and and the interactions between the two through and. - the study of living things also know as biology. Biology includes the physics and chemistry of living things, as well as their origin behavior. Biologists study the different ways that organisms grow, survive, and reproduce. There is overlap between different areas of science. The Big Ideas of Physical Science - The universe is both very old and very big. - A very small amount of the universe is matter, All matter that you are familiar with is made up of building blocks called atoms. - cause changes in. The laws of physics allow these changes to be calculated exactly.

3 - exists in many forms. can be transferred from one form or object to another, but can never be destroyed. Science is both a process and a body of knowledge. As more knowledge is added, the models that science uses to describe the universe change. Be skeptical. Ask questions. Be aware that the scientific facts of today might be changed as knowledge grows. However, believe in the scientific process that has discovered them. 1.2 Using the Scientific Approach An organized plan for gathering, organizing, and communicating information is called a. Can be used to search for the answer to a question. Can vary from case to case, depending on the question and how the researcher decides to look for an answer. What is the goal of the scientific method? Scientific Methods - information that you obtain through your senses. - a proposed answer to a question. In an experiment, any factor that can change is called a variable. - causes a change.

4 - changes in response to the variable. - an experiment in which only one variable, the variable, is deliberately changed at a time. - Describes how facts apply to a hypothesis. - a well-tested explanation for a set of observations or experimental results. Once a hypothesis has been supported in repeated experiments, scientists can begin to develop a theory. #1 Label with the correct terms for one example of the scientific method.

5 #2 Identify the following as a part of the Scientific method. Test whether speed affects how wet you get in the rain. Scientists determined that running in the rain keeps you drier The faster your speed, the drier you will stay. How does speed affect how wet you get in the rain? - a statement that summarizes a pattern found in nature. Example: Newton s of gravity is a scientific that has been verified over and over. Scientists have yet to agree on a that explains how gravity works. A describes an observed pattern in nature without attempting to explain it. The explanation of such a pattern is provided by a. Why are scientific models useful? A model is a representation of an object or event. A street map is a model of a city.

6 Safety plays an important role in science. Laboratory work may involve flames or hot plates, electricity, chemicals, hot liquids, sharp instruments, and breakable glassware. Always follow your teacher s instructions and the directions exactly. 1.3 Measurement - is a way of expressing a value as the product of a number between 1 and 10 and a power of 10. Example: the speed of light is about 300,000,000 meters per second. In scientific notation, that speed is m/s. The exponent tells you that the decimal point is really places to the of the 3. For numbers less than 1 that are written in, the exponent is. Example: An average snail s pace is meters per second. In, that speed is m/s. The exponent tells you how many decimal places there are to the of the 8.6 To multiply numbers written in scientific notation, you multiply the numbers that appear the multiplication signs and the exponents. Example: (3.0 x 10 8 m/s) x (5.0 x 10 2 s ) = (This is about the distance between the sun and Earth.) When dividing numbers written in scientific notation, you divide the numbers that appear before the exponential terms and the exponents. Example:(1.5 x m) (3.0 x 10 8 m/s) =

7 What units do scientists use for their measurements? Scientists around the world use the same system of measurements so that they can readily interpret one another s measurements. - the straight line distance between two points. - the quantity of matter in an object or sample. Quantity Unit Symbol Length Mass Temperature Time Amount of substance Electric current Luminous intensity Additional SI units, called, are made from combinations of base units. - the amount of space taken up by an object. - the ratio of an object s mass to its volume.

8 Formula: Quantity Unit Symbol Area Volume Density Pressure Pascal ( kg/m s 2 ) Pa Energy Joule (kg m 2 /s 2 ) J Frequency Hertz (1/s) Hz Electric charge Coulomb (A s) C - indicates how many times a unit should be multiplied or divided by 10. Si Prefixes Prefix Symbol Meaning Multiply Unit by Billon (10 9 ) 1,000,000,000 Million (10 6 ) 1,000,000 Thousand (10 3 ) 1000

9 Tenth (10-1 ) 0.1 or 1 10 Hundredth (10-2 ) 0.01 or Thousandth (10-3 ) or Millionth (10-6 ) Billionth (10-9 ) or or is a ratio of equivalent measurements used to convert a quantity expressed in one unit to another unit. Example 1km 1000m 1000 m 1 km Convert the height of Mount Everest, 8848 meters, into kilometers. x = km - a gauge of how exact a measurement is. - are all the digits that are known in a measurement, plus the last digit that is estimated. How does the precision of measurements affect the precision of scientific calculations? - the closeness of a measurement to the actual value of what is being measured.

10 Example: suppose a digital clock is running 15 minutes slow. Although the clock would remain precise to the nearest second, the time displayed would not be accurate. - an instrument that measures temperature, or how hot an object is. 5 C = ( F ) F = ( 9 C) The SI base unit for temperature is the A temperature of 0K, or 0, refers to the lowest possible temperature that can be reached. In degrees Celsius, this temperature is C. To convert between and degrees Celsius, use the formula: K = 1.4 Presenting Scientific Data In order for new to be useful, it must be reported in a clear, organized manner. Like the news, scientific data become meaningful only when they are organized and communication. How do scientists organize data? - relates two variables -- a manipulated variable/independent variable and a responding variable/dependent variable.

11 - useful for showing changes that occur in related variables. The variable is generally plotted on the The variable is plotted on the Sometimes the data points in a graph yield a straight line. The steepness, or, of this line is the ratio of the change to the corresponding change. Formula: - a relationship in which the ratio of two variables is constant. The relationship between the mass and the volume of water is a great example. Example: A 3 cm 3 sample of water has a mass of 3 grams A 6 cm 3 sample of water has a mass of 6 grams A 9 cm 3 sample of water has a mass of grams.

12 - a relationship in which the product of the two variables in a constant. Example: A flow rate of 0.5 gallon per minute will fill the pot in 2 minutes. A flow rate of 1 gallon per minute will fill the pot in 1 minute. A flow rate of 2 gallons per minute will fill the pot in - often used to compare a set of measurements, amounts, or changes. - shows how a part or share of something relates to the whole. How can scientists communicate experimental data? - a process in which scientists examine other scientists work. Encourages comments, suggestions, questions, and criticism from other scientists. Based on their peers responses, the scientists who submitted their work for review can then reevaluate how to best interpret their data.