1. Chapter One A chemistry- study of matter and the changes that matter undergoes -looks at behavior of atoms and molecules matter- anything that has mass and takes up space atoms- submicroscopic particles that are the building blocks of matter molecules- two or more atoms joined together -the properties of substances depend on atoms and molecules that compose them example- H 2 O and H 2 O 2

2. Branches of Chemistry 1) physical -studies the behavior of substances ex- how plastics work 2)analytical -studies the composition of substances ex- blood tests 3) organic -studies substances containing carbon ex- sugars

3. 4)inorganic -studies substances not containing carbon ex- salts, some acids 5)biochemistry -studies chemical processes in living organisms ex- digestive, respiratory, circulatory systems pure chem- studies chemistry just for the sake of knowledge alone applied chem- takes that knowledge to attain a specific goal

4. What makes science different from other subjects? scientific method- systematic approach to problem solving -acquiring knowledge about natural world Steps of the Scientific Method 1)Propose Problem/ Ask a Question -usually begins with an observation

5. 2)Gather Info -I-net, books, radio, interviews, newspapers, magazines, TV, videos 3)Form a Hypothesis -an educated guess, tentative explanation 4)Test Hypothesis Through Experimenting -experiment should be designed around hypothesis -for results to be accepted, the experiment must produce the same results over and over again

6. control- does not change variable- what is being changed - only one variable can be tested at a time independent/manipulated variable- what is changed on purpose dependent/responding variable- what happens in response to the manipulated variable being changed

7. 5)Analyze Results -observations and data should be colleted during experiment -organize data into tables, graphs, charts 6)Accept/Refute Hypothesis -based on hypothesis and results 7)Repeat scientific law- brief statement that summarizes past observations and predicts future ones -laws define how nature behaves -we generally accept laws as true without question

8. example- law of conservation of mass -states that matter can neither be created nor destroyed -laws can often times be equations theory- time tested idea that is widely accepted by the scientific community -theories will explain, laws will not example- Dalton’s Atomic Theory -states that all matter is composed of small indestructible particles called atoms

9. States of Matter solids- have definite shape and volume -atoms or molecules are tightly packed in fixed locations -atoms/molecules vibrate, but do not move or slide past one another Can be: crystalline- arranged in patterns with repeating order (salt, diamonds) amorphous- no order or repeating pattern (charcoal, plastic)

10. liquids- have definite volume, but no definite shape, take on the shape of their container -atoms/molecules are free to move gases- take both the shape and volume of their container -atoms/molecules have plenty of space between them and are free to move -this makes gases compressible

11. Classifying Matter substances- composed of only a single type of atom or molecule -chemical formulas or chemical symbols can be written from substances Substances can be: elements- substances that cannot be broken down into simpler substances -all found on the periodic table compounds- two or more elements chemically combined -ex- NaCℓ or H 2 SO 4

12. mixtures- composed of two or more different types of matter combined physically in variable proportions Types of mixtures heterogeneous- particles can be picked apart and separated ex- chicken soup, salad homogeneous- uniform composition, the same throughout, particles cannot be separated physically ex- Kool-Aid, iced tea

13. Separating Mixtures decanting- pouring off the water filtering- use filter paper, separate solid and liquid (page 10 figure 1.6) distillation- heat to boil off liquid, then recondense liquid and collect in a separate flask (page 10 figure 1.5)

14. Physical changes- alter only appearance, but not composition -usually reversible ex- boiling water, carving wood Physical property- property that a substance displays without changing its composition ex- melting and boiling point, color, odor

15. Chemical changes- alter the composition of matter, transform into different substances -usually irreversible ex- iron rusting, wood burning Chemical property- property that a substance displays only by changing its composition by ways of a chemical change