Scientific Methods Section 2 Bellringer Which do you think is more important: imagination or knowledge? Can one exist without the other? Reflect on this

Scientific MethodsSection 2

Bellringer

Which do you think is more important: imagination or knowledge? Can one exist without the other? Reflect on this in your science notebook. You may want to think of some famous scientists to write about in your answer. Then share your answer with the class and have a debate.

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What Are Scientific Methods?


• Follow the Steps Scientific methods are the ways in which scientists follow steps to answer questions and solve problems. The next slide shows how scientific methods work.




Ask a Question


• Make Observations Looking for answers may include making more observations.

• Accurate Observations No matter what observations reveal, they are useful only if they are accurately made and recorded.


Form a Hypothesis


• What Is a Hypothesis? A hypothesis is a possible explanation or answer to a question.

• Is It Testable? To be useful, a hypothesis must be testable.

• Predictions Before scientists can test a hypothesis, they must first make predictions. A prediction is a statement of cause and effect that can be used to set up a test for a hypothesis.


Test the Hypothesis


• Under Control A controlled experiment tests only one factor at a time and consists of a control group and one or more experimental groups.

• Designing an Experiment Designing a good experiment requires planning. Every factor should be considered.

• Collecting Data If an experience produces the same results again and again, scientists can be more certain about the effect the variable has on the outcome of the experiment.


Analyze the Conclusions


• Organize the Data After scientists finish their tests, they must analyze the results. Scientists must organize the data so that they can be analyzed.


Draw Conclusions


• After Analyzing the Data After scientists have analyzed the data from several experiments, they can draw conclusions.

• Is It the Answer? Finding an answer doesn’t always end an investigation. Often, that answer begins another investigation. In this way, scientists continue to build knowledge.


Communicate Results


• Organize the Data Scientists form a global community. After scientists complete their investigations, they communicate their results to other scientists.

Scientific ModelsSection 3

Think about this. . .

Answer the following questions in your science journal: • What is a model? • Name several types of models. • What models have you used in your own life? Then share your answers in a discussion with the class.



Types of Scientific Models

• Physical Models A toy rocket and a plastic skeleton are examples of physical models.

• Mathematical Models A mathematical model may be made up of numbers, equations, or other forms of data.

• Conceptual Models The third type of model is the conceptual model. Some conceptual models represent systems of ideas. Others compare unfamiliar things with familiar things.



Benefits of Models

• What Can Models Be Used For? Models are often used to represent things that are very small or very large. Models may also represent things that are very complicated or things that no longer exist.



Building Scientific Knowledge• Scientific Theories An explanation that ties together many related facts, observations, and tested hypotheses is called a theory.

• Scientific Laws In science, a law is a summary of many experimental results and observations.

• Combining Scientific Ideas Ideas from physical and earth science can be combined with ideas from life science.

• Scientific Change If new evidence contradicts an accepted idea, scientists must be willing to reexamine the evidence and reevaluate their reasoning.


Tools, Measurement, and SafetySection 4

Bellringer

Why do you think scientists use tools such as graduated cylinders and stopwatches? Where in your home do you find objects that are used for precise measurement? Do you think scientific activities ever happen in your home? Why or why not? Record your thoughts in your science notebook.



Computers and Technology

• What Is Technology? The application of science for practical purposes is called technology.

• Computers and Science Computers can be used to create graphs, solve complex equations, and analyze data. Computers also help scientists share data and ideas with each other and publish reports about their research.



Tools for Seeing

• Compound Light Microscope A compound light microscope is an instrument that magnifies small objects so that they can be seen easily. The next slide shows a compound light microscope.

• Electron Microscope In electron microscopes, tiny particles called electrons are used to produce magnified images.


Compound Light MicroscopeSection 4



Measurement

• The International System of Units In the late 1700s, the French Academy of Sciences began to form a global measurement system now known as the International System of Units (also called SI, or Système International d’Unités). Today, most scientists and almost all countries use this system.



Measurement continued

• Length A meter is the basic SI unit of length.

• Volume Volume is the measure of the size of an object in three-dimensional space. Volume is often given in liters.

• Mass A measure of the amount of matter in an object is mass. The kilogram is the basic unit for mass.



Measurement continued

•Temperature Temperature is the measure of how hot an object is. Scientists often measure temperature in degrees Celsius.

• Area Area is the measure of an object’s surface. The units for area are square units, such as square meters.

• Density The ratio of the mass to volume of a substance is density. Units often used for density are grams per milliliter.


Common SI Units and ConversionsSection 4



Safety Rules!

• Safe Scientific Investigations Safety rules must be followed at all times during a scientific investigation.

• Get Permission Before starting any scientific investigation, obtain your teacher’s permission.

• Understand Procedures Read the lab procedures completely and carefully before you start.

• Learn Safety Symbols Pay attention to safety information and caution statements.


The World of Life ScienceChapter 1

Concept Map


Use the following terms to complete the concept map on the next slide: scientific methods, observations, controlled experiments, living things, life science, drawing conclusions.

Concept MapChapter 1


Concept MapChapter 1


Documents

Scientific Methods Section 2 Bellringer Which do you think is more important: imagination or knowledge? Can one exist without the other? Reflect on this