Science Tools Chapter 1

“Science is a way of thinking much more than it is a body of knowledge “Science is a way of thinking much more than it is a body of knowledge.”  -Dr. Carl Sagan

1.1 Main Ideas Scientists explore the natural world by using skills: Observing Classifying making models Inferring predicting. Scientists form and test their ideas through scientific investigation (experimentation).

Classifying Cancer Colonies Scientists observed the effects of different tree samples on cancer cells. Each petri dish began with 10 colonies of cancer cells. The diagrams show the results after being treated with the tree samples. How many cancer cell colonies are in each petri dish?

1.2 Main Ideas The SI system allows scientists to compare data and communicate with each other about the results of scientific investigations SI Unit Measures meter length kilogram mass newtons weight cubic centimeters volume g/ml or g/cc density seconds time kelvin temperature

Prefixes of SI Units What words belong in the blank spaces in this table? This table uses the meter as a base, which is the SI unit for length.

Some SI Units of Measure

Predicting Density Density determines if an object floats or sinks.

Density Point out the meniscus in each graduated cylinder. What is the volume of water in each?

Densities of Common Substances Which substances in the table would float in water? Which substances would sink in water?

Kelvin and Celsius Scales Liquid in a thermometer moves up or down as temperature changes.

1.3 Main Ideas Estimation Accuracy Precision significant figures Mean Math tools Math Skills Estimation Accuracy Precision significant figures Mean Median Mode Range Percent error

Accuracy and Precision Four teams measure the mass of the turtle. The turtle’s actual mass is 153.7 grams.

Maximum Wind Speed, Strongest Storms of Each Year, 2002–2009

Adult Male Florida Black Bear Masses Researchers measured the masses of five adult male Florida black bears. The bears were in their natural habitat during the summer months.

1.4 Main Ideas Scientists use graphs to: Identify trends Make predictions Recognize anomalous data

Nesting Numbers The information in the graph shows the number of leatherback sea turtle nests on Juno Beach, Florida, between 2004 and 2009.

Graphing the Speed of Sound As temperatures rise, so does the speed at which sound travels through the air.

Sea Life Diving Data The diving depths of several sea creatures were measured and recorded in the data table. Imagine what a bar graph of this information would look like. How would you arrange the animals in order from shallowest divers to deepest divers along the x axis? Give the graph a title.

The data table shows the number of tourists visiting a Florida 4th of July celebration between 2006 and 2009.

1.5 Main Ideas People conduct scientific inquiry by gathering evidence about the natural world and proposing explanations based on this evidence. People test a hypothesis by designing experiments that follow reliable scientific principles A scientific explanation is a generalization that makes sense of observations by using logical reasoning

Controlling Variables A student wants to test whether shampoo cleans oily hair better than water alone. The student mixes oil with water in one test tube and oil with soapy water in another test tube. She watches to see when the mixture separates. What is the independent variable? What is the dependent variable?

Percentage of Students Finished Testing Over Time Information organized in a data table can easily be made into a graph. This data table shows the percent of students who finished testing over a period of time. Where would you plot the data on the graph?

A student dipped squares of nylon, polyester, and cotton in water and hung them up to dry. He then measured the amount of time they took to dry.