Chapter One: Studying Life • 1.1 Measurements • 1.2 Thinking Like a Scientist • 1.3 Graphs
Investigation 1A Measurement and Data • Is there a relationship between human “wingspan” and height?
1.1 Measurement and Data • A measurement is a value that tells the amount of something. • A measurement has a quantity and a unit. How do we measure tiny living things?
1.1 Measurement and Data • A unit is a fixed amount of something. • The centipede below is 5 centimeters (5 cm.) in length. • The earthworm is 5 inches (5 in.) in length. • Which is a larger unit, centimeters or inches?
1.1 International System of Measurement • Units allow people to communicate amounts. • To make sure their measurements are accurate, scientists use a set of standard units that have been agreed upon around the world. • The International System of Measurement is known as the S.I. (System International).
1.1 Length • Length is a measurement of distance. • How should we measure the length of this fish?
1.1 Area • Area is a measurement of how much surface something has.
1.1 Volume • Volume is a measurement of the amount of space something occupies.
1.1 Measuring Liquids • The surface of a liquid forms a curve rather than a straight line. • That curve is called a meniscus. • If the meniscus curves downward, read the volume at the bottom of the curve.
1.1 Mass • Mass is the measure of the amount of matter that makes up something.
1.1 Temperature • Temperature is a measure of how hot or cold something is. • As particles move faster on average, the temperature goes up. • As particles move slower on average, the temperature goes down.
1.1 Measuring Solutions • A solution is a mixture of two or more substances that are evenly distributed at the molecular level. • Scientists use units of concentrationwhen measuring levels of dissolved substances in water.