CHAPTER ONE The Chemical World

CHEMISTRY 10: Chp 1 Chem. 10 is an introduction to a physical science. A science is the observation, identification, description, experimental investigation, and theoretical explanation of natural phenomena. Chemistry is the science of the composition, structure, properties and reactions of matter, especially of atomic and molecular systems.

CHEMISTRY 10: Chp 1 What do you need to start this class? - Some math skills (Math 104 or equivalent) - Some study skills - Ability to read/comprehend English textbook - A previous Chemistry class (HS or 160) Will it be hard to do? - Try to reduce anxiety with group activities - Exams - we will have some practice first - In lab: just use caution and listen!!! - Learn the language of chemistry!

CHEMISTRY 10: Chp 1 What does SCUBA stand for? (Self-contained underwater breathing apparatus) - Every area of life has its own “lingo” and acronyms - You will learn the “lingo of chemistry”

CHEMISTRY 10: Chp 1 Learning takes time Due next class: fill in the plan with your class schedule, work schedule and other necessary activities, then mark exactly when you plan to put in these nine hours, plus your other classes’ study time. Learning takes concentration Learning involves study techniques

Natural Phenomena experimentally investigate theoretically explain observe describeidentify

Matter compositionstructure propertiesreactions

Structure Determines Properties Everything is made of tiny pieces called atoms and molecules Chemists believe that the properties of a substance are determined by the kinds, numbers and relationships between these pieces

The Scientific Method: Definitions Law: Statement of natural phenomena to which no exceptions are known under the given conditions. A law is not an explanation. Hypothesis: A trial explanation of certain facts that provides a basis for further experimentation. Theory: Well-established hypothesis. An explanation of the general principles of certain phenomena with considerable evidence or facts to support it.

STEPS FOR THE SCIENTIFIC METHOD 1. Collect facts or data that are relevant to the problem or question at hand. This is usually done by experimentation. 2. Analyze the data to find trends (regularities). 3. Formulate a hypothesis that will account for the data and that can be tested by further experimentation.

STEPS FOR THE SCIENTIFIC METHOD 4. Plan and do additional experiments to test the hypothesis. 5. Modify the hypothesis to ensure compatibility with the experimental data.

Some Definitions Matter: Anything that has mass and occupies space. Mass : The quantity or amount of matter that an object possesses. - Fixed - Independent of the object’s location Weight: A measure of the earth’s gravitational attraction for an object. - Not fixed - Depends on the object’s location.