Chapter 2.1 Measurements and Calculations Table of Contents

Copyright © by Holt, Rinehart and Winston. All rights reserved.

ResourcesChapter menu

Table of Contents

Measurements and Calculations

Section 1 Scientific Method Section 2 Units of Measure !Section 3 Using Scientific Measurements

Chapter 2.1



Objectives

• Describe the purpose of the scientific method. !

• Distinguish between qualitative and quantitative observations. !

• Describe the differences between hypotheses, theories, and models.

Section 1 Scientific MethodChapter 2

End Show© Copyright Pearson Prentice Hall

Slide of 25

Thinking Like a Scientist

In 1928, Alexander Fleming noticed that bacteria he was studying did not grow in the presence of a yellow-green mold. In 1945, Fleming shared a Nobel Prize for Medicine with Howard Florey and Ernst Chain, who led the team that isolated penicillin.

2.1



Scientific Method

• The scientific method is a logical approach to solving problems by observing and collecting data, formulating hypotheses, testing hypotheses, and formulating theories that are supported by data.



Thinking Like a Scientist >

Slide of 25

Alchemy

Alchemy - a pseudoscience that included serious scientists but also mystics and fakes who were obsessed with the idea of changing cheap metals into gold.

How did alchemy lay the groundwork for chemistry?

2.1


Slide of 25

Thinking Like a Scientist > Alchemy

Alchemists developed the tools and techniques for working with chemicals.

2.1

End Show

Slide of 25

© Copyright Pearson Prentice Hall

Thinking Like a Scientist > Alchemy

Alchemists developed processes for separating mixtures and purifying chemicals. They designed equipment that is still in use today including beakers, flasks, tongs, funnels, and the mortar and pestle.

Mortar and Pestle

2.1



Slide of 25

An Experimental Approach to Science


How did Lavoisier help to transform chemistry?

2.1



Slide of 25


Lavoisier helped to transform chemistry from a science of observation to the science of measurement that it is today.

2.1

End Show

Slide of 25


Thinking Like a Scientist > An Experimental Approach to Science

Lavoisier designed a balance that could measure mass to the nearest 0.0005 gram. He also showed that oxygen is required for a material to burn.

Reconstruction of Lavoisier’s Laboratory

2.1



Observing and Collecting Data

• Observing is the use of the senses to obtain information. !

• data may be • qualitative (descriptive) • quantitative (numerical) !

• A system is a specific portion of matter in a given region of space that has been selected for study during an experiment or observation.




Visual Concepts

! Click below to watch the Visual Concept.

Visual Concept

Qualitative and Quantitative Data

Chapter 2

http://my.hrw.com/sh/hc6_003036809x/student/ch02/sec01/vc01/hc602_01_v01fs.htm




Slide of 25

The Scientific Method

The Scientific Method

What are the steps in the scientific method?

2.1



Visual Concepts


Visual Concept

Scientific Method

Chapter 2



End Show

Slide of 25


Thinking Like a Scientist > The Scientific Method

The scientific method is a logical, systematic approach to the solution of a scientific problem.

!

Steps in the scientific method include making observations, testing hypotheses, and developing theories.

2.1

End Show

Slide of 25



Making Observations When you use your senses to obtain information, you make an observation.

Suppose you try to turn on a flashlight and it does not light. An observation can lead to a question: What’s wrong with the flashlight?

2.1



Formulating Hypotheses

• Scientists make generalizations based on the data. !

• Scientists use generalizations about the data to formulate a hypothesis, or testable statement.

• Hypotheses are often “if-then” statements.


End Show

Slide of 25



Testing Hypotheses A hypothesis is a proposed explanation for an observation.

You guess that the flashlight needs new batteries. You can test your hypothesis by putting new batteries in the flashlight. If the flashlight lights, you can be fairly certain that your hypothesis is true.

2.1



Formulating Hypotheses




Visual Concepts


Visual Concept

Hypothesis

Chapter 2





Testing Hypotheses

• Testing a hypothesis requires experimentation that provides data to support or refutes a hypothesis or theory. !

• Controls are the experimental conditions that remain constant. !

• Variables are any experimental conditions that change.


End Show

Slide of 25



An experiment is a procedure that is used to test a hypothesis. When you design experiments, you deal with variables, or factors that can change.

• The variable that you change during an experiment is the manipulated variable, or independent variable.

• The variable that is observed during the experiment is the responding variable, or dependent variable.

• mnemonic device: “DRY MIX” (Dependent, responding variable is graphed on y-axis; Maniuplated or independent variable is graphed on the x-axis.

2.1



Theorizing

• A model in science is more than a physical object; it is often an explanation of how phenomena occur and how data or events are related.

• visual, verbal, or mathematical • example: atomic model of matter, a 3-D computer

simulation of the solar system, • or an analogy such as a comet is like a big ball of

snow mostly made of ice.




Visual Concepts


Visual Concept

Models

Chapter 2





• A theory is a broad generalization that explains a body of facts or phenomena that has been tested.

• examples: atomic theory or cell theory

Theorizing

End Show

Slide of 25



Developing Theories

Once a hypothesis meets the test of repeated experimentation, it may become a theory.

• A theory is a well-tested explanation for a broad set of observations

• A theory may need to be changed at some point in the future to explain new observations or experimental results

2.1

End Show

Slide of 25



Scientific Laws

A scientific law is a concise statement that summarizes the results of many observations and experiments.

A scientific law doesn’t try to explain the relationship it describes. That explanation requires a theory.

Laws often can be shown as mathematical formulas such as the law of the universal gravitational Force (F): F = (Gm1m2)/d2.

2.1



Scientific Method


End Show

Slide of 25



Steps in the Scientific Method

The Scientific Method2.1

End Show

Slide of 25


Thinking Like a Scientist > Concept Map of Scientific Method

Click here for Concept Map Activity with Scientific Method

30

http://my.hrw.com/sh/hc6_003036809x/student/ch02/hc602_m.htm



Slide of 25

Collaboration and Communication

Collaboration and Communication

What role do collaboration and communication play in science?

2.1

End Show

Slide of 25


Thinking Like a Scientist > Collaboration and Communication

No matter how talented the players on a team, one player cannot ensure victory for the team. Individuals must collaborate, or work together, for the good of the team.

When scientists collaborate and communicate, they increase the likelihood of a successful outcome.

2.1

End Show

Slide of 25



Collaboration Scientists choose to collaborate for different reasons.

• Some research problems are so complex that no one person could have all of the knowledge, skills, and resources to solve the problem.

• Scientists might conduct research for an industry in exchange for equipment and the time to do the research.

2.1

End Show

Slide of 25



Collaboration isn’t always a smooth process. You will likely work on a team in the laboratory. If so, you may face some challenges. But you can also experience the benefits of collaboration.

2.1

End Show

Slide of 25



Communication Scientists communicate face to face, by e-mail, by phone, professional journals, and at national & international conferences.

Scientists publish their results in scientific journals. Articles are published only after being reviewed by experts in the author’s field.

2.1


Slide of 25

End Show

2.1 Section Quiz.

1. Lavoisier is credited with transforming chemistry from a science of observation to a science of

a. speculation.

b. measurement.

c. hypotheses.

d. theories.


Slide of 25

End Show

2.1 Section Quiz.

2. A hypothesis is

a. information obtained from an experiment.

b. a proposed explanation for observations.

c. a concise statement that summarizes the results of many of experiments.

d. a thoroughly tested explanation for a broad set of observations.


Slide of 25

End Show

2.1 Section Quiz.

3. Why are articles in scientific journals the most reliable source of information about new scientific discoveries?

a. The articles are reviewed by experts in the author's field.

b. Any article that is submitted is published.

c. Everyone has access to the information.

d. The articles are short and easy to read.


Slide of 25

End Show

Online Self-Check Quiz

Complete the online 2.1 Quiz and record answers. Ask if you have any questions about your answers.

!

click here for online Quiz 2.1

(7 questions)

You must be in the “Play mode” for the slideshow for hyperlink to work.

!

http://my.hrw.com/sh/hc6_003036809x/student/ch02/sec01/hc602_01sq.htm


Slide of 27

End Show

VIDEOS FOR ADDITIONAL INSTRUCTION

Additional Videos for Section 2.1 Scientific Method - (2 videoclips)!1) Scientific Method Steps (5:17)2) Science Experiments (5:20)

http://brightstorm.com/science/biology/foundation-of-biology/scientific-method-steps

http://brightstorm.com/science/biology/foundation-of-biology/science-experiments



End of Chapter 2.1 Show

Date post:	12-Apr-2022
Category:	Documents
Upload:	others
View:	3 times
Download:	0 times

Chapter 2.1 Measurements and Calculations Table of Contents

Documents