CHEMISTRY

• study of matter and the changes it undergoes

  chemistry
• a systematic approach in investigating nature

  scientific method
• can be qualitative (subjective) or quantitative (measured)


  observations
• a tentative explanation


  hypothesis
• tests the hypothesis and involves data gathering


  experiments
• contains the results of the experiment

  interpreting results
• rejects or accepts the hypothesis

  conclusion
• summarizes what happens; always the same under the same conditions

  law
• an attempt to explain why it happens

  theory
• characterized by rigidity; incompressible; fixed volume and shape

  solid
• particles without regular and repetitive arrangement

  amorphous
• particles with repetitive arrangement

  crystalline
• characterized by surface tension & viscosity; incompressible; fixed volume but no shape

  liquid
• easily compressible; no shape & volume

  gas
• ionized form of gas

  plasma
• solid to liquid


  melting
• liquid to solid


  freezing
• liquid to gas


  vaporization
• gas to liquid


  condensation
• solid to gas


  sublimation
• gas to solid


  deposition
• has distinct properties; doesn't vary; cannot be separated by any physical process

  pure substance
• cannot be decomposed into simpler substances

  element
• shiny. conductive, malleable


  metal
• lack luster, insulator, brittle


  non-metal
• has properties of both metal and non-metal

  metalloid
• composed of two or more elements combined in fixed proportions

  compound
• one or more atoms of carbon are covalently linked to atoms of other elements

  organic
• two or more elements combined, nearly always in definite proportions

  inorganic
• a pure compound always contains definite or constant proportions of elements by mass


  law of definite proportion
• has variable composition; can be separated into two or more substances

  mixture
• consists of physically distinct particles

  heterogeneous
• uniform in its properties

  homogeneous
• homogeneous to the naked eye; heterogeneous under a microscope

  colloid
• components include the dispersing medium and the dispersed phase

  tyndall effect
• closeness of values obtained from identical measurements of a quantity

  precision
• closeness of a measurement to its true value

  accuracy
• way of writing numbers that are too big or small to be written conveniently

  scientific notation
• digits that carry meaning contributing to precision

  significant figures
• all non-zero numbers are significant