Section 1.1 & 1.3 Lecture What is Chem? & THE SCIENTIFIC METHOD.

Section 1.1 & 1.3 LectureWhat is Chem?

& THE SCIENTIFIC METHOD

QuickTime™ and a decompressor

are needed to see this picture.

What Is Chemistry?

Chemistry is the study of matter and the changes that matter undergoes.

1.1



What Is Chemistry?


1.1

Matter is anything that has mass and occupies space.

Matter = STUFFQuickTime™ and a

decompressorare needed to see this picture.

What Is Chemistry?


1.1

Matter is anything that has mass and occupies space.

Matter = STUFFIf it is not matter, then it is empty space.



What Is Chemistry?

EVERYTHING is CHEMISTRY!!

1.1

Because living and nonliving things are made of matter, chemistry affects all aspects of life and most natural events.

Why Study Chemistry?1.1

Chemistry can help explain the natural world, prepare people for career opportunities, and produce informed citizens.

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.

Making Observations

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


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?


Testing Hypotheses

A hypothesis is a proposed explanation for an observation

1.3 The Scientific Method



Testing Hypotheses

A hypothesis is a proposed explanation for an observationYou guess that the flashlight needs new batteries.




Testing Hypotheses


You can test your hypothesis by putting new batteries in the flashlight.




Testing Hypotheses


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.




An experiment is a procedure that is used to test a hypothesis. When you design experiments, you deal with variables (things that change).



–The variable that is changed on purpose is the manipulated variable, or independent variable.



–The variable that is changed on purpose is the manipulated variable, or independent variable.

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


If it is the sun that is damaging the leaves on my fern,

then moving it to a spot with less sun should stop more fronds from dying.




HYPOTHESIS!




HYPOTHESIS!

EXPERIMENT!


Hypothesis- Bubble size depends on gum flavor



Experiment- measure bubble size using different gum flavors




Manipulated variable- gum flavor




Manipulated variable- gum flavor

Responding variable- bubble size


A controlled variable is something that could affect the outcome of your experiment, so because it is not of interest it must be removed or kept constant for every trial.

Controlled variables-

Brand, quantity, …


Failure to identify and control competing factors can make an experiment invalid.


The best experiments have just one manipulated variable and all other variables are controlled.


The best experiments have just one manipulated variable and all other variables are controlled.

This makes it certain that changes in responding variables are a result of that one experimental manipulation because it was the only thing different.


Matter- anything with mass and volume

Hypothesis- a proposed explanation for an

observation

Experiment- a procedure used to test a hypothesis.

In ReviewThe Scientific Method

Developing Theories

If a hypothesis is supported by repeated experimentation, it may become a theory.


Developing Theories


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


Developing Theories


–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.


Scientific Laws

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


Scientific Laws

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

A scientific law states what happens but does not explain how it happens.

That explanation requires a theory.


Steps in the Scientific Method


Hypothesis- an explanationExperiment- tests hypothesisTheory- an explanation that is supported by so many different experiments that we agree it is TRUTH. Scientific Law- what happens


Hypothesis- an explanationExperiment- tests hypothesisTheory- an explanation that is supported by so many different experiments that we agree it is TRUTH. Scientific Law- what happensLAW- Ships disappear on the horizonOld hypothesis- the ship falls off the world

because it is flatCurrent theory- the ship moves out of view

because the world is a sphere.


HOMEWORKYour first homework assignment is to complete

the section 1.1 &1.3 review.

Assignments are due at the start of the next class.

Completed homework is stamped during bellwork to show that it was completed on time.

Keep all stamped work until collected before the quiz.

Section 1.1 & 1.3 Lecture What is Chem? & THE SCIENTIFIC METHOD.

Documents

Transcript of Section 1.1 & 1.3 Lecture What is Chem? & THE SCIENTIFIC METHOD.