Chapter One Science Skills
Daily Assignment • What is Science? Where does it come from?
What is Science • Science begins with curiosity and ends with discovery. • Science can also happen by accident. • Science versus Technology • Science aims to understand the world • Technology aims to change the world
Branches of Natural Science • Physical Science • Chemistry and Physics • Earth and Space Science • Geology and Astronomy • Life Science • Biology
Physical Science • Space and Time • Matter and Change • Forces and Motion • Energy
The Scientific Method • The Scientific Method is the process by which scientists approach the solving of a problem. • Sometimes scientists make discoveries by accident, but many are solved in this manner.
Identify the Problem • Present the problem in a question form. Examples: • Which paper towel is the most absorbent? • Which cell phone gives the most bars in our area?
Gather information • Use observations to gain perspective and data about your problem.
Hypothesis • Make a testable solution to the problem. • Base your hypothesis on the information you’ve collected
Design an Experiment • Plan an experiment to test the hypothesis. • This should be performed under controlled conditions.
Perform the Experiment • Follow your plan as written. Collect data and note any problems with your procedure.
Analyze the data • Use the information collected to support or refute your hypothesis • Make a choice Hypothesis not supported by data Data supports my hypothesis
Conclusion • Communicate your results. • Make charts and/or graphs to summarize your results. • If your hypothesis is wrong, come up with a new one!
The Variables • Independent Variable: is the item which you will change in the experiment. • Dependent Variable: is the item that will change depending on what independent variable is used. • Control: the experiment run changing only one variable at a time.
Example Experiment • Suppose my electricity bill was higher than normal recently (Problem). • I would notice that my bills have been getting higher recently (Gathering Data) • I believe that this is caused by my old refrigerator (Hypothesis)
Example Experiment • I plan to test all of my appliances using an Ohm meter to see which draws the most electricity (Designing the Experiment) • I test all of my appliances to see which draws the most current (Perform the Experiment) • I then analyze the data and notice that my refrigerator does draw the most power, but it has not been running more than usual. (Conclusion?)
Example Experiment • My hypothesis was wrong, so I need to get a new one! • Perhaps something has been used more frequently recently? • It turns out that my ceramic heater was the culprit because it has been working overtime to keep up with the very low temperatures!!
Can you put the Scientific Method to the test ? Over this weekend, you are to perform an experiment Come up with a question that you want answered Go through the scientific method step by step and try to get an answer.
Can you put the Scientific Method to the test ? • Come in on Monday either with an answer or a new hypothesis. • Make sure you have all the steps represented of what you did. • This does not have to be a lengthy report, just an explanation.
Theories vs. Laws • What’s the difference? • A Scientific Law describes a pattern in nature without explaining it. A theory is the accepted explanation of that pattern. • Examples:
Lab Procedures • Any time we are in a lab setting, the following rules must apply • Do not touch, take, taste, handle, caress, or drink anything without my permission • We may have dangerous chemicals, sharp objects, or other lethal / poisonous materials in the classroom • Make sure your work area is clean before and after the lab
Lab Procedures • Labs will be most likely accompanied by a lab report, so make sure you are paying close attention to what you are doing. • Always follow my directions exactly. • There is to be no horse play during labs. • All materials and tools are to be returned to me at the end of the lab in their original condition.
Scientific Notation • A short-hand way of writing large numbers without writing all of the zeros. • The number is written as a base X power of 10. • 2.3 x 10 5
The Distance From the Sun to the Earth • 93,000,000 miles
Step 1 Move decimal left Leave only one number to the left of decimal 93,000,000 .= 9.3000000
Step 2 Write number without zeros 93,000,000 = 9.3
Step 3 Count how many places you moved decimal Make that your power of ten 7 93,000,000 = 9.3 x 10
98,500,000 = 64,100,000,000 = 279,000,000 = 4,200,000 = 9.85 x 107 6.41 x 1010 2.79 x 108 4.2 x 106 Practice Problem Write in scientific notation. Decide the power of ten.
What about really small numbers? Picture of a dust mite on the top of a pinhead The size of dust mite is 0.00000000024 meters
For numbers less than zero • Move the decimal right, so there is one numeral to the left of the decimal. 0.00000000024 = 2.4 • Count the number of spaces you moved the decimal. This becomes the exponent. The exponent is negative. 2.4 X 10 -10
More Practice Problems 734,000,000 = _____________ 870,000,000,000 = __________ 90,000,000,000 = ___________ 0.0000000034500 = _________ 0.0000122 = ______________ 0.00454000 = _____________ On these, decide where the decimal will be moved.
Scientific Notation to Standard Form When the exponent is positive, move the decimal to the right 3.4 x 105 in scientific notation 3.40000 --- move the decimal 340,000 in standard form
6,270,000 90,100 Write in Standard Form Move the decimal to the right. • 6.27 x 106 • 9.01 x 104
When the exponent is negative, move the decimal to the left. Add zero’s as spacers. Scientific Notation to Standard Form • 4.33 x 10-6 in scientific notation • 0.00000433 --- move the decimal left
Write in Standard Form 7.11 x 10-4 5.001 x 10-8 2.34 x 10-20 0.000711 0.00000005001 0.0000000000000000000234 Move the decimal to the left.
Introduction to the Metric System Click here
Daily Assignment • Multiply (no calculators) the following: 3 X 5 = a x 2 = 2 4 3 4ac
A History of Measurement In all traditional measuring systems, short distance units were based on the dimensions of the human body.
A History of Measurement Historical = current = measurement Uncia = Inch = width of the thumb Cubit = Foot = length of a foot (length of forearm) Span = Yard = length of arm from nose to finger
Standard Of Measurement An exact quantity that people agree to use for comparison. Two criteria a standard must meet: Accessible to all Never changing
The English System Uses historical units based on an agreed upon standard. 1 foot = 12 inches 1 yard = 3 feet The English system is used primarily in the USA only.
Length Is defined as the distance between two points Length is measured using aRuler English units of length are inch, foot, yard, and mile.
Mass Is defined as the amount of matter in an object. Is measured using aBalance English units are ounces, pounds, tons
Volume Is the amount of space an object takes up Volume - solid Liquid volume
Volume (continued) Liquid English units are ounce, pint, quart, gallon Solid English units are pint, quart bushel, peck,
Time Is defined as the interval between two events Is measured using a stopwatch or a clock
Temperature Is defined as the amount of energy contained in an object Is measured using aThermometer
Daily Assignment Estimate your age as a decimal Ex : Birthday June 1st = 15.5 years Birthday Feb. 5th = 15.1 years Now, convert your age in years to your age in seconds.