7. Elements, Compounds, Mixtures

Element
  • A substance that cannot be broken down into simpler substances by chemical means.
  • consists of only one type of atoms.
  • Melts & boils at a fixed and constant temperature.

Compound
  • A substance containing 2 or more elements chemically combined together.
  • Atoms of each element are combined in a fixed ratio.
  • Properties different from that of its components.
  • Cannot be separated by physical methods.
  • Has a fixed and constant melting & boiling point.
  • Melts & boils at a fixed and constant temperature.

Mixture
  • A substance containing 2 or more elements or compounds that are not chemically combined.
  • Components in the mixture is not combined in a fixed ratio.
  • Properties same as that of their components.
  • Easily separated by physical methods e.g. distillation, filtration etc
  • Melts & boils over a range of temperatures.