science chapter 6, a classification of substances.

• Conductivity of electricity


  An important property in which substances can differ
• Substance conducts electrical current

  • The substance must consist of charged particles
  • The charged particles must be able to move freely
• Types of substances


  • Metals
  • Salts
  • Molecular substances
• Metals


  Conduct current in the solid and liquid phase
• Salts


  Conduct current in the liquid and dissolved phase
• Molecular substances


  Do not conduct current in any phase
• Metals consist of one kind of atom and the formula equals the symbol
• The formula of a salt always contains both metal and non-metal kinds of atoms
• Salts do not conduct current in the solid phase at macro level but it does at the liquid phase
• A solution of salt in water also conducts electricity
• The charged particles of salt can only move freely in the liquid or dissolved phase
• In the formula of a molecular substance, only non-metal kinds of atoms occur
• Molecular substances do not conduct current in any phase, meaning there are no freely moving charged particles in any phase of a molecular substance