Chemistry mid point

• What would the ending be if you combined two elements together?

  Ide
• What would the ending be if you combined three elements together?

  Ate
• How do you display if there are more than one elements on an element?

  Add a little number next two it
• What does it mean if they is a big number infront of all the elements?

  It means there is that many elements for all of the elements following it
• What do you do if they is a big number at the start of the element sequence and a small number next to one element?

  Times them together to find the total number of elements for that element
• What is a chemical reaction?

  A change that takes place when one or more substances called reactants form one or more new substances called products
• What does the state symbol "s" stand for?

  Sodium
• What does the state symbol "l" stand for?

  Liquid
• What does the state symbol "g" stand for?

  Gas
• What does the state symbol "aq" stand for?

  Aqueous (dissolved in water)
• In chemical processes, which type of number are you only allowed to use?

  Big numbers
• How do you balance equations?

  By adding numbers only either side to make it equal on both sides
• What is an element?

  A single element that is not combined with anything else
• What is a compound?

  A substance composed of two or more elements chemically bonded together.
• What is the process of filtration?

  1. Fold the filter paper into quarters to create a pocket and place in the funnel.
  2. Place the funnel in the conical flask.
  3. Pour the salt, sand and water solution gently into the filter paper in the funnel.
  4. The residue left in the filter paper is the sand which I have now successfully separated
• What is the process of crystillisation?

  1. Place the evaporating dish on top of the tripod.
  2. Pour a small amount of filtrate into the dish.
  3. Heat on a gentle flame until nearly all of the water has evaporated.
  4. Turn the bunsen burner off as soon as you start to see salt crystals form. Make sure you do this straight away so the salt crystals don't spit out at you.
  5. Place the dish on the window cill for the rest of the water to evaporate, leaving behind the salt crystals.
• What is chromatography?

  The process that can be used to find out what colours are mixed together in different paints, dyes or inks
• What does relative solubility of the components of a mixture determin?

  How far the ink travels up the paper during chromatography. The more soluble a substance is in the solvent the further up the paper it is carried
• What is distillation?

  A process that uses evaporation and condensation to obtain a solvent (liquid) from a solution
• Why would simple distillation not work properly?

  If the difference between the two boiling points is less than 25 degrees
• What is the radius of an atom?

  0.0000000001m
• What is the weight of an atom?

  1 x 10-23
• What charge are neutrons?

  Neutrons
• What is the mass of protons and neutrons?

  1
• What charge are protons?

  Positive
• What charge are electrons?

  Negative
• What did James Chadwick (1932) do?

  He discovered the existence of neutrons
• What did John Dalton (1766/1844) do?

  He stated that all matter is made from atoms, that atoms are identical in mass and properties and that atoms cannot be created or destroyed
• What did Niels Bohr (1885-1962) do?

  He stated that electrons occupy separate shells around the nucleus, that electrons travel around the atoms and their energy levels can go up if given enough energy.
• What did Ernest Rutherford (1911) do?

  They stated that most mass is concentrated in the centre and he discovered the proton. He also disproved the "plum pudding" model.
• What did Ernest Marsden and Hans Geiger (1908) do?

  They did a gold foil experiment which led them to discover that an atom has a nucleus that is positively charged.
• What JJ Thomson (1897) do?

  He discovered electrons and that they were like the atom. He came up with the "plum pudding" model to represent electrons.
• What is the mass number?

  The number of protons + the number of neutrons
• What is the atomic number?

  The number of protons
• What is the charge of an atom?

  Neutral
• What is the number of protons equal to?

  The number of electrons
• Is the mass number on the top or the bottom?

  The top
• Is the atomic number on the top or the bottom?

  The bottom
• How do you work out the number of neutrons on an element?

  Do the mass number - the atomic number
• Where do the electrons go on the shells?

  The electrons occupy shells or orbit around the nucleus of the atom