Mixtures

• Define the term 'mixture' in terms of chemistry

  two or more elements or compounds not chemically combined together
• State the five ways mixtures can be separated


  -filtration

  -crystallisation

  - simple distillation

  -fractional distillation

  -chromatography
• What is the purpose of filtration? give an example


  separate an insoluble solid from a liquid. (e.g. Separating sand from water).
• What is the purpose of evaporation? give an example


  separate a soluble solid from a liquid. e.g (Obtaining salt crystals from saltwater)
• What is the purpose of Crystallisation? give an example


  obtain pure crystals of a soluble solid e.g (Making copper sulfate crystals)
• What is the purpose of Distillation? give an example


  separate a liquid from a mixture based on boiling points. e.g (Obtaining water from saltwater)
• State an example of fractional distillation


  Separating ethanol and water.
• What is the purpose of chromatography? give an example


  separate substances in a mixture based on their solubility and movement through a medium. e.g ( Separating dyes in ink).
• How did the new evidence from the scattering experiment led to a change in the atomic model?


  the positive charge is not spread out, atoms contain a nucleus a positive charge and most of the mass
• Give three differences between both the plum pudding model of the atom and the nuclear model of the atom.


  plum pudding:

  -positive charge is spread evenly throughout the atom.

  -Electrons are stationary

  -No nucleus, atom is a single mass.

  
  

  nuclear model :

  electrons move around the nucleus

  atom is empty space, allowing particles to pass through

  Atom has positively charged nucleus at its center.
• "Nucleus at the Center" means ...?


  -tiny, dense, positively charged core.
• "Electrons in Orbits" means ...?


  Electrons move around the nucleus in shells or energy levels, atom has mostly empty space
• Define the term 'mixture' in terms of chemistry

  two or more elements or compounds not chemically combined together
• State the five ways mixtures can be separated


  -filtration

  -crystallisation

  - simple distillation

  -fractional distillation

  -chromatography
• What is the purpose of filtration? give an example


  separate an insoluble solid from a liquid. (e.g. Separating sand from water).
• What is the purpose of evaporation? give an example


  separate a soluble solid from a liquid. e.g (Obtaining salt crystals from saltwater)
• What is the purpose of Crystallisation? give an example


  obtain pure crystals of a soluble solid e.g (Making copper sulfate crystals)
• What is the purpose of Distillation? give an example


  separate a liquid from a mixture based on boiling points. e.g (Obtaining water from saltwater)
• State an example of fractional distillation

  Separating ethanol and water.
• What is the purpose of chromatography? give an example

  separate substances in a mixture based on their solubility and movement through a medium. e.g ( Separating dyes in ink).
• How did the new evidence from the scattering experiment led to a change in the atomic model?


  the positive charge is not spread out, atoms contain a nucleus a positive charge and most of the mass
• Give three differences between both the plum pudding model of the atom and the nuclear model of the atom.


  plum pudding:

  -positive charge is spread evenly throughout the atom.

  -Electrons are stationary

  -No nucleus, atom is a single mass.

  
  

  nuclear model :

  electrons move around the nucleus

  atom is empty space, allowing particles to pass through

  Atom has positively charged nucleus at its center.
• "Nucleus at the Center" means ...?


  -tiny, dense, positively charged core.
• "Electrons in Orbits" means ...?

  Electrons move around the nucleus in shells or energy levels, atom has mostly epm