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G. Chemistry 1

Substances’ properties and reactions.

Properties to identify a substance: 

  • intensive: independent of amount (color of gold)
  • extensive: depend on amount. (the quantity of gold in a sample)
  • chemical: behavior in a chemical reaction
  • physical: melting and boiling point

by measuring its properties and comparing them with the properties for known substances. 

The law of conservation of mass. 


  1. density
  2. solubility (saturated, unsaturated)
  3. Color; absorption spectrum



to get: heating red mineral cinnabar (process)

Properties Uses
high density liquid barometer, manometer
can dissolve many mental, forming solutions (amalgams) a silver-mercury-tin amalgam in teethfillng

exist: combined form in clays and rocks. 

Process to obtain the element: Hall and Herroult process extracting Al from bauxite. 


Properties Uses


have fixed compositions

elements don’t keep their original form. 

methods to resolve compounds into their elements:

  • heating 
  • electrolysis
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no fixed compositions. 

each substances (either elements or compounds) remains its chemical identity. 

  • Homogeneous: solution = solvent + solutes (brass)
  • Heterogeneous: rocks

methods to separate mixtures to get elements or compounds: 

  1. Ho solid-liquid mixture – distillation
  2. He solid-liquid mixture – filteration
  3. chromatography: due to different solubility and/or absorption  (gas-liquid chromatography: car exhaust test or drug test. )


  • length
  • volume
  • mass
  • temperature
Uncertainties in measurements: significant figures (*/; +-)
scientific notation
round off
A number that is spelled out (parameters and prefix independent variable) does not affect the number of significant figures. 

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