C1

• what is an element?

  all of the atoms are the same
• what is a compound?

  two or more elements chemically combined in fixed proportions
• what is a mixture?

  a combination of elements or compounds that are not chemically combined.
• what is filtration?

  used to separate an insoluble solid from a liquid.
• how does filtration work?

  pour your mixture into the filter funnel lined with filter paper, the liquid passes through the tiny pores in the filter paper into the conical flask
• what is crystallisation?

  used to separate a soluble solid from a liquid.
• how does crystallisation work?

  leaving the substance for a couple days to evaporate and it leaves crystals of the solid behind. we can also gently heat the substance
• what is simple distillation?


  separation of dissolved solid from liquid while keeping the liquid.
• what is a condenser?

  cold water runs through the condenser to keep the internal class tube cold
• what happens during simple distillation?

  1. heat the solution using a bunsen burner
  2. as we heat , the liquid starts to turn into a vapour.
  3. the vapour rises up the glass tube and increases the temp. on the thermometer.
  4. the vapour passes through the condenser, condensing the vapour back into a liquid in the flask.
• what is fractional distillation?


  Separation of a mixture into its components based on their different boiling points.
• what does the fractionating column do in fd?

  it condenses vapours that have a higher boiling point.
• how does fractional distillation work?

  boil the flask with the mixture of liquids in it with the lowest boiling point.

  the liquids begin to vaporise and rise up the fractionating column however the vapours with a higher boiling point will condense back into the flask.
• how does paper chromatography work?

  1. draw a pencil line near the bottom of the chromatography paper.
  2. next place however many dots you want on the line as long as it fits
  3. place the bottom of the paper in a solvent.
  4. the solvent seeps up the paper and it dissolves the ink in the two coloured dots.
  5. a pure compound will produce a single spot where as a mixture will produce more than one spot.
• why is the paper in paper chromatography considered the stationary phase?

  cause it doesnt move
• why is the solvent considered the mobile phase in pc?

  cause it moves.
• why do we draw our starting line in pencil?

  if we drew in pen, the pen ink will dissolve in the solvent aswell.
• what is abundance ?

  how common something is
• what is the equation for relative atomic mass?

  (mass number of isoptope 1 x Percent abundance of isoptope 1) + (mass number of isotope 2 x Percent abundance of isotope 2) / 100
• what is group 0 referred too as?

  noble gasses
• why are noble gases unreactive?

  they are stable as they have a full outer shell
• what happens to the boiling point of the noble gases as we go down group 0?

  increases
• what happens when metals react?

  they lose electrons to achieve a full outer energy level
• what is an ion?


  an atom with a charge
• what is group 1 called?

  the alkali metals
• how do group 1 metals react with oxygen and chlorine?


  react rapidly as we go down group 1
• why do group 1 metals become more reactive as we go down the group?

  as we move down group 1, there is a greater distance between the positive nucleus and the negative outer electron. as this distance increases the electron is less attracted to the nucleus.
• what is another reason group 1 metals become more reactive as we go down the group?

  the outer electron is repelled by electrons in the internal energy levels and it decreases the attraction to the nucelus.
• what is group 7 called?

  halogens
• every group 7 element forms a molecule consisting of two atoms joined by a covalent bond.
• In Group 7, the further down the group an element is the higher its relative molecular mass, melting point and boiling point.
• In Group 7, the reactivity of the elements decreases going down the group.
• group 7 elements form a covalent compound when they react with other non-metal elements
• when halogens react with metals, they form ionic compounds.
• when any halogen reacts with a metal the halogen atom gains one electron and forms an ion with a -1 charge.
• as we go down group 7, there is greater distance between nucleus and outer electron making it harder to gain electrons
• as we go down group 7 there is greater shielding of outer electron
• a more reactive halogen can displace a less reactive halogen from an aqueous solution of its salt.
• mendeleev arranged the elements in order of increasing atomic weight.
• mendeleev would switch the order of specific elements so they fitted the patterns of other elements.