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

What Is Chemistry? Chemistry is the study of matter and the changes that matter undergoes. 1.1

What Is Chemistry? Chemistry is the study of matter and the changes that matter undergoes. 1.1 Matter is anything that has mass and occupies space. Matter = STUFF

What Is Chemistry? Chemistry is the study of matter and the changes that matter undergoes. 1.1 Matter is anything that has mass and occupies space. Matter = STUFF If 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. The Scientific Method

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? The Scientific Method

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 observation You guess that the flashlight needs new batteries. 1.3 The Scientific Method

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. 1.3 The Scientific Method

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. 1.3 The Scientific Method

An experiment is a procedure that is used to test a hypothesis. When you design experiments, you deal with variables (things that change). 1.3 The Scientific Method

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. 1.3 The Scientific Method

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 observed during the experiment is the responding variable, or dependent variable. 1.3 The Scientific Method

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. The Scientific Method

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! The Scientific Method

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!  EXPERIMENT! The Scientific Method

Hypothesis- Bubble size depends on gum flavor The Scientific Method

Hypothesis- Bubble size depends on gum flavor Experiment- measure bubble size using different gum flavors The Scientific Method

Hypothesis- Bubble size depends on gum flavor Experiment- measure bubble size using different gum flavors Manipulated variable- gum flavor The Scientific Method

Hypothesis- Bubble size depends on gum flavor Experiment- measure bubble size using different gum flavors Manipulated variable- gum flavor Responding variable- bubble size The Scientific Method

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, … The Scientific Method

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

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

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. The Scientific Method

Matter- anything with mass and volume Hypothesis- a proposed explanation for an observation Experiment- a procedure used to test a hypothesis. In Review The Scientific Method

Developing Theories If a hypothesis is supported by repeated experimentation, it may become a theory. The Scientific Method

Developing Theories If a hypothesis is supported by repeated experimentation, it may become a theory. –A theory is a well-tested explanation for a broad set of observations. The Scientific Method

Developing Theories If a hypothesis is supported by 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. The Scientific Method

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

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. The Scientific Method

Steps in the Scientific Method 1.3 The Scientific Method

Hypothesis- an explanation Experiment- tests hypothesis Theory- an explanation that is supported by so many different experiments that we agree it is TRUTH. Scientific Law- what happens The Scientific Method

Hypothesis- an explanation Experiment- tests hypothesis Theory- an explanation that is supported by so many different experiments that we agree it is TRUTH. Scientific Law- what happens LAW- Ships disappear on the horizon Old hypothesis- the ship falls off the world because it is flat Current theory- the ship moves out of view because the world is a sphere. The Scientific Method

HOMEWORK Your 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.