Pure and Impure substances

• • A Pure element or compound contains only one substance , with no other substances mixed in.
• • Impure materials may be mixtures of different elements , compounds or both
• How can the purity of an element or compound be tested?

  • The purity of an element or compound can be establish or tested using its melting point
• Impure substances melt over range of temperatures , not just one temperature. (the boiling point of an impure substance is often less than that of the pure substance)