2026-2027 Daniela Payne Chem 280 Midterm Study Guide: Chapters 1-9 & Homework Sets West Coast University CHAPTER 1-9 MIDTERM CHAPTER 1 DEFINITIONS: Chemistry: Chemistry is the science that tries to understand what matter does by understanding what molecules do. The science that studies the connections between the properties of matter and the particles that compose that matter. Scientific Method: makes use of observations, hypotheses, laws, theories, and experiments. Observation: When a given sample of gasoline is burned in a closed container, the mass of the container and its contents does not change involve measuring or observing some aspect of nature Hypo: tentative interpretations of the observations. Laws: A short statement that summarizes a large number of observations Theories: models that explain and give the underlying causes for observations and laws Atomic theory Analytical vs Quantification: how much, makes how much involves measurement as part of observation. 1g of H = 6.022x 10 ^23 atoms QUESTIONS: 1. 2. 3. 4. 5. 6. 7.
WHAT ARE THE STEPS IN SCIENTIFIC METHOD (overview): Classify each statement: obs, hypo, laws, theories. SCIENTIFIC THEORY: A gas is composed of small particles in constant motion. WATER MOLECULE CONTAINS: 2 H + 1 oxygen. AT ROOM TEMP WATER IS LIQUID BC: water repels each other AKA characteristics. IS EVERYTHING CHEMICAL: T. IE] N2 78.1 %, 02 21 %, PENICAL(CARBON) Mass equals reactions and products: chemical rxn we don’t loss any mass LAW of CONSERVATION
8. Where can you find chemicals? You can find chemicals in the hardware store, a chemical stockroom, All around you and even inside of you CHAPTER 2 DEFINITIONS: Metric system vs SI units C > F > K * = temperature Meter (m); length
Mass kg kilogram, g grams Time: Seconds: mins Volume: liters