1. Introduction to Chemistry
Chpt 1

2. What is chemistry?
The study of the composition of matter and the changes it undergoes
Matter is anything that has mass and takes up space
Everything!!
5 traditional areas of study
Organic – carbon based
Inorganic – not carbon based
Biochemistry – living things
Analytical - composition of matter
Physical – mechanisms, rate & energy transfer that accompany changes in matter

3. Pure chemistry – pursuit of knowledge for its own sake
Applied chemistry – how can the knowledge be applied to society
technology

4. Scientific Method
Common steps that scientists use to gather information and solve problems
They are not fixed steps, but generally involve the following: Observe, Hypothesize, Experiment, Collect and Analyze Data, Drawing Conclusion, Reporting, Revision and Verification

5. Observe – watch, take note of, pay attention to Hypothesis
Observe – watch, take note of, pay attention to Hypothesis -A testable explanation for a question or problem -An educated guess as to the answer to a question or problem -Scientists may test a hypothesis by conducting an experiment *either disprove or support the hypothesis

6. Experimenting A. An experiment is a procedure that tests a hypothesis by the process of collecting information under controlled conditions. B. A controlled experiment i. Some experiments involve 2 groups: a. The control group: The standard for comparison, the group that is not tested on b. The experimental group: The test group in which all conditions are kept the same except for the single condition being tested

7. Designing an experiment. i
Designing an experiment i. In a controlled experiment only one condition is changed at a time a. We only change one condition so we know which condition caused the results b. the condition in the experiment that the experimenter changed is the independent variable ii. While changing the independent variable, the scientist observes a second condition that results from the change. This condition is the dependent variable. a. changes in this variable depend on changes in the independent variable iii. Not all investigations are controlled experiments a. field work does not usually include a control group, where laboratory work is usually controlled

8. Theories and Laws i. Theory a. An explanation of a natural phenomenon that is supported by a large body of evidence b. Continual verification and refinement of a hypothesis results in a theory c. A valid theory enables scientists to predict new facts and relationships d. It explains a natural phenomenon e. Can change ii. Laws or Principles a. Certain facts of nature b. Description of a natural phenomenon c. Doesn’t change

9. Matter and Change
Chpt 2

10. Properties of Matter
Extensive – depends on the amount of matter present (ex. mass or volume)
Intensive – depends on the type of matter present (ex. conductivity, malleability, flammability
Physical property - a property that can be determined without changing the nature of the substance
-characteristics of the substance
ex. Color, state, texture, melting point, boiling point, density, hardness, etc
Chemical property– a property that describes a substances ability to participate in chemical reactions
-describes how a substance acts
ex. Reactivity, flammability, combustibility

11. States of Matter
all matter is made of particles, the type and arrangement of particles in a sample determine the properties of that matter
matter comes in 3 common states (there are other states, but not used in general chemistry):
-solid - fixed volume and shape, particles held tight and rigid (usually close together), don’t compress or expand much

12. States of Matter
-liquid – fixed volume but not shape, particles not held as tightly together as solids, particles can slip past one another, therefore liquids can flow and take the shape of their containers, not very compressible but expand slightly
-gas – neither fixed volume nor shape, particles are weakly attracted, they move independently of one another, particles move at high speed, will fill any container they occupy, easily compress and expand
*vapor – gas form of a substance that is
usually solid or liquid at room temperature

13. a pure substance is one thing 2 types of pure substances
a pure substance is a sample of matter that has a definite composition, and definite chemical and physical properties
a pure substance is one thing
ex. Gold, salt, sugar, water, hydrogen, etc.
2 types of pure substances
Elements and compounds

14. Physical Changes
-physical changes – the identity of the substance doesn’t change
*the arrangement, location, and speed of
the particles may change
*ex. change of state, ripping paper,
dissolving sugar in tea, crushing chalk

15. Mixtures
Mixtures
matter that is made up of two or more pure substances
they are not chemically bonded, and they are not in a specific ratio
they can be separated into their pure substances by physical means
ex. Filtration, distillation, evaporation, etc.

16. heterogeneous – the pure substances are not evenly distributed
2 types of mixtures
homogeneous – the pure substances are evenly distributed giving the mixture a uniform structure and composition
the different parts cannot be seen even under a microscope
also referred to as solutions
heterogeneous – the pure substances are not evenly distributed
you can see the different parts
different regions have different properties

17. Elements & Compounds elements – contain only kind of atom
*a substance that cannot be separated or
broken down into simpler substances by
chemical means
*all atoms of the same elements have the
same structure each element has its own
unique set of physical and chemical
properties
*each element has its own symbol, and they
are listed on the periodic table (ex. C)

18. some elements exist as single atoms, they are called monatomic elements
some elements exist in groups of atoms, if they come in twos we call them diatomic elements (there are 7 common ones: Br, I, N, Cl, H, O, F)
some elements have more than one form, they are called allotropes
ex. Oxygen can come as O2 or O3
the different forms have different properties

19. represented by a formula using symbols (ex. H2O)
compounds – made of more than one type of atom chemically bonded in a specific ratio
represented by a formula using symbols (ex. H2O)
if there is only one atom of a certain type, we use no subscript
several types of formulas
molecular formulas, structural formulas , ball and stick models , space filling
compounds can be further classified by their type of bond or what elements they are made of
ex. Ionic/covalent or organic/inorganic
can only be separated into its elements by chemical means

20. Chemical Changes
chemical changes – the identity of the substance(s) changes and a new substance is formed
-even though the substances are changed, the atoms that make them up are just rearranged, atoms are not created or destroyed just rearranged

21. evidence of chemical changes
production of a gas
formation of a precipitate
change in energy
color change
-these are all possible indicators that a
chemical change is occurring, some of these may occur during a physical change as well, the more that are occurring the more likely it is a chemical change

22. Substance vs mixture
Flow chart p.44

23. Periodic Table Intro Elements are organized in a special arrangment
in the periodic table
Rows are called periods
Columns are called groups or families

24. Law of conservation of mass – matter is neither created nor destroyed it just changes forms
Law of conservation of energy – energy is neither created nor destroyed it just changes forms