Chemistry paper 1

• C1 Atomic Structure
• Atoms are the particles that make up everything

  What are atoms?
• A substance in which all the atoms are the same


  What is an element?
• periodic table


  Where are elements shown?
• Around 118


  How many elements are there?
• a substance that contain two or more elements chemically combined

  What is a compound?
• compounds are usually different to the elements that they are made from

  Describe the properties of compounds
• A substance with different elements or compounds not chemically combined


  What is a mixture?
• Sand and water as they are not chemically combined and can be separated by physical means

  Give an example of a mixture
• A substance that has any elements chemically joined

  What is a molecule?
• the elements in a molecule and the number of atoms of each element


  What does a chemical formula tell you about a molecule?
• Each element symbol starts with a capital letter, if there is a second letter it is in lower case


  How is a chemical formula presented?
• Give an example of a chemical formula

  
• State symbols show the physical state of the substance solid (s), liquid (l), gas (g), or dissolved in water (aq)


  What are state symbols?
• -Strong

  -Good conductors of heat and electricity

  -High melting and boiling points


  Name three properties of Metals
• -Weak

  -Bad conductors of heat and electricity

  -Low melting and boiling points


  Name three properties of Non-Metals
• Filtration, crystallisation, distillation or chromatography

  State the four different ways of separating mixtures
• Pour your mixture onto the filter paper through the filter funnel, the liquid simply passes through the filter paper into the flask. The insoluble solid cannot pass through so the residue remains on the paper


  Describe the process of filtration
• Use the method of filtration to filter off any excess soluble solid. Transfer the mixture into an evaporating basin and gently heat until crystals start to form. Leave the solution to cool and crystals should form.

  Describe the process of crystallisation
• Poor the solution in the distillation flask and attach a water condenser to it. Put a beaker at the outlet of the condenser. evaporate the mixture by heating it (the solution with the lowest boiling point will evaporate first. The vapours condense in the condenser. The rest of the solution is left in the flask

  Describe the process of simple distillation
• Take a strip of filter paper and draw a line on the bottom of the paper. Put a small drop of ink on the line, take a beaker full of water up to the line and put the filter paper in. As the water moves up we see different colours on the paper these are the dyes in the ink


  Describe the process of chromatography
• Simple distillation


  How can you get pure water from sea water?
• It can only be used to separate things with very different boiling points


  What are the problems with simple distillation?
• Put mixture in flask and add fractional Column to the top, then heat. The different liquids have different building points so they will evaporate at different temperatures. The liquid with the lowest boiling point evaporated first.

  Fractional distillation
• Doesn't show the realistic shape that particles are in, doesn't show the forces between the particles so you can't see how strong they are

  Disadvantages of the particle theory

  
• that they are tiny spheres that cannot be divided


  What were the early ideas of the structure of atoms?
• An atom is a ball of positive charge with negative electrons in it


  Describe the plum pudding model

  
• Rutherford took a piece of gold foil, he then fired tiny positive alpha particles it and He discovered most particles went through the foil and sometimes they bounced back


  Describe Rutherford gold foil experiment.

  
• He discovered that atoms are mainly empty space as most of the alpha particles went straight through the gold atoms and that the nucleus of the atom is very small as only a small number of alpha particles bounce back

  What did Rutherford discover from these observations?
• most of an atom is empty space, in the centre is the nucleus which contains protons and neutrons around the edge we find electrons

  Describe the structure of the nuclear model
• What is the Relative mass and the relative charge of protons, neutrons and electrons?

  
• Because atoms have have no overall charge


  Why do atoms have the same number of protons as electrons?
• A charged particle, positive or negative ions


  What is an Ion?
• Atoms of the same element with different numbers of neutrons are called isotopes

  What is an Isotope?
• Top number. Its the number of proton and neutrons combined


  What is the mass number of an element?
• Bottom number. It's the number of protons in an atom, which is the same as the number of electrons


  What is the atomic number of an element?
• A set of number to show the arrangement of electrons in their shells, eg. [2,6]

  What is an Electronic structure?
• C2 The periodic table
• He arranged the elements in order of increasing atomic mass, he saw that every eighth element reacted in a similar way


  What did John Newlands periodic table look like?
• He arranged the elements in order of increasing atomic mass, he switched the order of some elements to the fitted in the patterns of other elements. He left gaps for undiscovered elements


  What did Dmitri Mendeleev's periodic table look like?