Section 2: Methods of Scientists Scientists use scientific methods to structure their experiments and investigations. K What I Know W What I Want to Find Out L What I Learned

Essential Questions What are independent and dependent variables? How does experimentation and investigation differ? What are the differences between mass and weight? What is scientific notation and how is it used? Methods of Scientists Copyright © McGraw-Hill Education

Vocabulary Review New experiment scientific methods hypothesis independent variable dependent variable control Le Système International d’Unités (SI) scientific notation Methods of Scientists Copyright © McGraw-Hill Education

The Nature of Scientific Investigations Scientists use similar methods to gather data and communicate information. Scientific methods are a series of problem-solving procedures that helps scientists conduct experiments. A hypothesis is a testable explanation of a situation that can be supported or disproved by careful procedures. Copyright © McGraw-Hill Education Methods of Scientists

Visualizing Scientific Methods Scientific methods are used by scientists to help organize and plan their experiments and investigations. Methods of Scientists Copyright © McGraw-Hill Education

Add link to Animation from page 11 here. Visualizing Scientific Methods Concepts In Motion FPO Add link to Animation from page 11 here. Methods of Scientists Copyright © McGraw-Hill Education

Add link to BrainPOP here. Scientific Methods BrainPOP FPO Add link to BrainPOP here. Methods of Scientists Copyright © McGraw-Hill Education

The Nature of Scientific Investigations Experimentation An experiment is classified as an organized procedure that involves making observations and measurements to test a hypothesis. Methods of Scientists Copyright © McGraw-Hill Education

The Nature of Scientific Investigations The independent variable in an experiment is the factor that is changed by the experimenter. A dependent variable is a factor that is affected by changes in the independent variable. A control is used in an experiment to show that the results of an experiment are a result of the condition being tested. Methods of Scientists Copyright © McGraw-Hill Education

Add link to Virtual Lab here. How is a controlled experiment performed? Virtual Lab FPO Add link to Virtual Lab here. Methods of Scientists Copyright © McGraw-Hill Education

The Nature of Scientific Investigations An investigation involves observation and collecting data but does not include a control. Methods of Scientists Copyright © McGraw-Hill Education

The Nature of Scientific Investigations Analysis and conclusions During a scientific experiment, all data are carefully recorded. Once an experiment is complete, graphs, tables, and charts are commonly used to display data. These data are then analyzed so that a conclusion can be drawn. Methods of Scientists Copyright © McGraw-Hill Education

The Nature of Scientific Investigations Analysis and conclusions Many times, a conclusion does not support the original hypothesis. In such a case, the hypothesis must be reevaluated and further research must be conducted. Methods of Scientists Copyright © McGraw-Hill Education

Measurement Le Système International d’Unités (SI) is a modern version of the metric system based on a decimal system. Methods of Scientists Copyright © McGraw-Hill Education

Measurement Length Mass The SI unit for length is the meter (m). The amount of matter in an object is called mass. The SI unit of mass is the kilogram (kg). Methods of Scientists Copyright © McGraw-Hill Education

Measurement Weight Weight is a measure of the gravitational force on an object. The SI unit for force is the newton (N). Methods of Scientists Copyright © McGraw-Hill Education

Measurement Area and volume Area is the amount of surface included within a set of boundaries. The SI unit for area is square meters (m2). Volume is the amount of space occupied by an object. The SI unit for volume is cubic meters (m3). Methods of Scientists Copyright © McGraw-Hill Education

Measurement Density Density is the measure of the amount of matter that occupies a given space. The SI units for density are expressed in grams per cubic centimeter (g/cm3), grams per milliliter (g/mL), and kilograms per cubic meter (kg/m3). Methods of Scientists Copyright © McGraw-Hill Education

Measurement Time Time is the interval between two events. The SI unit for time is the second (s). Methods of Scientists Copyright © McGraw-Hill Education

Measurement Temperature Temperature is a measure of the average kinetic energy of the particles that make up a material. The SI unit for temperature is the kelvin (K). Absolute zero is the coldest possible temperature. Methods of Scientists Copyright © McGraw-Hill Education

Scientific Notation In scientific notation, a number is expressed as a value between 1 and 10 multiplied by a power of 10. Examples The number of grains of sand on Earth is approximately 4,000,000,000,000,000,000,000 and would be written as 4 × 1021. The mass of Earth at 5,973,600,000,000,000,000,000,000 kg would be written as 5.9736 × 1024 kg. Methods of Scientists Copyright © McGraw-Hill Education

Review Essential Questions Vocabulary scientific methods hypothesis What are independent and dependent variables? How does experimentation and investigation differ? What are the differences between mass and weight? What is scientific notation and how is it used? Vocabulary scientific methods hypothesis independent variable dependent variable control Le Système International d’Unités (SI) scientific notation Methods of Scientists Copyright © McGraw-Hill Education