Chapter 1: The Nature of Science

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b. An example of this is you may stop the noise of the door by applying oil but you will not know what is causing this

D. Experiments test ideas

a. This means that even if an experiment does not give the desired results, it is not failure

b. An example of this is will oiling the hinges stop the noise? Often, as with Roentgen X rays, experimental results are surprising and lead scientists in new directions

E. Scientist use special tools

a. This means that sometimes scientists make observations by using tools made through advancements in technology

b. An example of this Is a Radio telescopes detect the radio waves given off by distant objects.

II. Units of measurement

a. Scientists use standards units of measure that together forms the international system of units, or SI

b. An example of this is Si stands for the French term le systeme internationale de unites

A. SI units are used for chemistry

a. This means that SI is based on the metric system and uses the seven

b. An example of this is That one of you classmates estimates that she drinks three gallons of water

B. SI prefixes are used for very large and very small measurements

a. This means that to avoid writing a lot of decimal places and zeros, you can use SI prefixes to express very small or very large numbers.

b. An example of this instead of saying the bird eggs is 5/100 m you can just say the egg is 5 cm

C. You can convert between smaller and larger numbers

a. this means that to convert a smaller unit, multiply the measurement by the ratio of the units so that you get a larger number.

b. An example of this is to change 185 cm to meter divide by 100

D. Measurements quantify your observations

a. This means that many observations rely on quantitative measurements.

b. An example of this is how much time did it take? And how big is it?

Organizing data

Key ideas:

• Why is organizing data an important science skill?

• How do scientist handle very large and very small numbers

• How can you tell the precision of a measurement

I. Presenting scientific data

A. This means that scientist use written reports and oral presentations to share their results, organizing and presentations data are important science skills

B. An example of this is if you try to determine the speed pf a chemical reaction, then you read the volume of gas in the cylinder

A. Line graphs show continuous changes

i. this means that a line graph is a good choice for displaying data that change continuously.

ii. An example of this is that the graph shows that the gas has been produced slowly for the first 20 seconds

B. Bar graphs compare the values of items

i. This means that a bar graph is useful when you want to compare similar data for several individual items or events

ii. An example of this is sow the temperature of melting metals

C. Pie graphs shoe the parts of a whole

i. This means that a pie graph is ideal for displaying data that are parts of a whole

ii. An example of this is a jacket may contain 66% nylon 30% polyester, and 4% spandex

II. Writing numbers in Scientific Notation

a. This means that to reduce the number of zeros in very big and very small numbers, you can express the values as simple numbers multiplied by a power of 10

b. An Example of this is 4.5 x 10 12

A. Use scientific notation to make calculations

i. This means that when you use scientific notation in calculations you should folloy the math rules for power of 10

ii. An example of this is when you multiply two values you add the powers of 10.

III. Using significant figures

i. This means that scientists use significant figures to show the precision of a measured quantity

ii. An example of this is the distance of a 4.1 m has two significant figures because thee measured value has two digits

B. Accuracy differs from precision

i. This means that precision and accuracy do not have the same meaning

ii. An example of this is if you measure the long jump with the tape measure that has a broken tip, you can still read 4.14 m precisely. But that number is not accurate because it is not the actual distance of the jump

C. Round your answers to the correct significant figures

i. this means that when you use measurement in calculations, the answer is only as precise as the least precise measurement used in the calculation

ii. An example of this is if you use a calculator to multiply 8.871 by 9.14, the display may show 81.08094 as an answer. But you do not know the are of the room to the neares 0.00001 m2