Chapter 1

Matter and Life

Chapter 1 suggested problems: 18, 24, 28, 30, 36, 38, 40, 44, 46, 48

links: the world's smallest billboard at http://www.almaden.ibm.com/vis/stm/atomo.html

Class Notes

  1. What is chemistry?

    1. A working definition

      1. Chemistry is the study of things made up of atoms and molecules

      2. It is the study of why they behave the way they behave

      3. It is the study of how to make them behave more usefully

    2. Fundamental branches of chemistry

      1. Analytical - the study of "what" and of "how much" is in substances

      2. Biochemistry - the chemistry of life and living things, based on organic chemistry

      3. Inorganic - the chemistry of all compounds that do not contain both carbon and hydrogen

      4. Organic - the chemistry of all compounds that contain both carbon and hydrogen

      5. Physical - the study of how the laws of physics affect atoms and molecules

    3. Why is chemistry relevant?

      1. A few examples: what problems do Ph.D. chemists I know study?

        1. Analysis of DNA and large biological molecules at http://www.che.uc.edu/fac_staff/limbach.html

        2. Blood clotting mechanisms

        3. The chemistry of cardiovascular disease

        4. Breast cancer detection

        5. Pharmaceuticals

        6. Fertilizers and pesticides

        7. Food chemistry

        8. Personal hygiene & cosmetics

        9. Chemistry of surfaces at http://www.chem.ualberta.ca/%7Emcdermot/home.html

        10. Composite materials

        11. Lubricants and additives

        12. Nerve gas detection and detoxification

        13. Detection of drugs and poisons

  2. What is matter?

  3. How is matter classified?

    1. States of matter - solids, liquids, gases (vapors)

      1. Changes of state (physical changes, phase changes) - melting, vaporization, sublimation, freezing, condensation, deposition

    2. Composition

      1. Element - all of the atoms are the same, can consist of more than one atom (O2, N2, S8, P4)

      2. Compound - made of two or more elements - H2O, CO2, CH3CH2OH

      3. Substance - cannot be separated into other kinds of matter by physical means (e.g., elements and compounds)

      4. Mixture - can be separated into other kinds of matter by physical means; e.g. salt dissolved in water

        1. Homogeneous mixture - uniform composition, properties, and appearance throughout the mixture - salt dissolved in water

        2. Heterogeneous mixture - do not have uniform composition, properties, and appearance throughout the mixture - pizza, granite, salt and sand

    3. What kinds of properties does matter have?

      1. Physical properties: properties which can be observed and measured without changing the composition of the material

        1. Physical properties: color, odor, state of matter, melting point, boiling point, heats of vaporization and fusion, density, solubility, metallic character, electrical and thermal conductivity, magnetic properties, crystal shape, malleability, ductility, viscosity, etc.

        2. Most common physical changes either involve changes of state (phase transitions) or are the consequence of mechanical processing (e.g. grinding, crushing, slicing, pulverizing, gluing pieces together, etc.)

      2. Chemical properties: the reactivity of a substance, how a substance changes its composition when it interacts with other substances

    4. The difference between changes of state (physical changes) and chemical reactions

      1. Physical changes - changes involving physical properties, or, changes in which there is no change to the chemical composition of the material(s) under observation

      2. Chemical changes (chemical reactions) - starting materials are consumed and new materials are formed due to the breaking and making of chemical bonds

        1. Chemical reactions may be indicated by color changes, the absorbing or release of energy (heat, light, sound electric), or by the formation of new materials such as gases, pure liquids, or solids (precipitates)

  4. How are chemical elements represented?

    1. Element - all of the atoms are the same

    2. 115 known elements, 88 are naturally occurring (see WebElements)

    3. 20 most abundant elements in the earth's crust (from "The Elements," John Elmsley; Oxford University Press, 1989.)
      element
      percent composition
      oxygen
      45.5
      silicon
      27.2
      aluminum
      8.3
      iron
      6.2
      calcium
      4.66
      magnesium
      2.76
      sodium
      2.27
      potassium
      1.84
      titanium
      0.63
      hydrogen
      0.15
      phosphorus
      0.11
      manganese
      0.11
      fluorine
      0.054
      barium
      0.039
      strontium
      0.038
      sulfur
      0.034
      carbon
      0.018
      zirconium
      0.016
      vanadium
      0.014
      chlorine
      0.013
      all others
      0.044

    4. 15 most abundant elements in human body (from Elemental Composition of the Human Body, found at http://www.neosoft.com/~uthman/elements_of_body.html)
      Element Mass of element in a 70-kg person
      per cent
      oxygen 43 kg
      61.4
      carbon 16 kg
      22.9
      hydrogen 7 kg
      10.0
      nitrogen 1.8 kg
      2.57
      calcium 1.0 kg
      1.43
      phosphorus 780 g
      1.11