C1 and C2

• What is the law of conservation of mass?

  no atoms are lost or made during a chemical reaction so the mass of the products equals the mass of the reactants
• What is filtration?


  Separates an insoluble solid from a liquid
• What is crystallization?


  Separates a soluble solid from a solution
• What is distillation?


  separates liquids with different boiling points
• What is fractional distillation?

  A process used to separate liquids using a fractional column and their different boiling points.
• What is the plum pudding model?

  It states that atoms are a ball of positive charge, with negative electrons embedded in it (JJ Thompson)
• What was Mendeleev's view of the periodic table?

  Put the elements into increasing atomic weight, switch some elements so they would fit the groups, then leave gaps for undiscovered elements.
• What was Bohr's model?

  Electrons travel around the nucleus in well defined paths called the orbit, in which different orbits contain electrons with different amounts of energy.
• What is an isotope?

  atoms with the same number of protons but different number of neutrons
• What is an ion?


  A charged atom
• What is Newlands Law of Octaves?

  Every eight element had properties similar to that of the first
• Why are Group 0 (noble gasses) unreactive?

  They have a very stable electron arrangements.
• What are alkali metals? (group 1)

  Soft solids at room temp, the reactivity increases down the group and so does their melting and boiling point.
• What are the halogens? (group 7)

  Non metallic elements, they have low melting and boiling points as they are small molecules made up of pairs of atoms. They do not conduct electricity and poor conductors or thermal energy.
• The trend of Group 1 metals?

  Reactivity increases down the group because the outer shell is less strongly attracted to the nucleus as the number of shells occupied increases. They lose electrons
• The trend of group 7 metals?

  Reactivity decreases down the group because the outer shell is decreased as the number of occupied shells increases. They gain electrons.
• What are transitioning metals?

  They are in the centre block, they are good conductors of electricity and thermal energy, high melting points, much more harder and dense than group 1 metals. Less reactive.
• Why does reactivity increase down group 1 metals?


  There are more occupied shells and the atoms get larger, so the electrons in the outermost shell are less strongly attracted by the nucleus so is lost easily.
• why does group 7 boiling points increase down the group?

  Size of molecule increases so intermolecular forces increase needing a large amount of energy to break the forces.
• What are the group 1 metals

  They are soft solids at room temperature, low densities and have low mpt and bpt.
• Why does colours move at different speeds during the experiment

  Different coloured inks have different levels of solubility, the more soluble inks, the further up the paper they will travel.
• RF = distance moved by substance / distance moved by solvent