C1: atomic structure

• Atom


  The tiny particles that make up all substances; the smallest part of an element that can exist
• Elements


  A susbtance made of only one type of atom
• Compound

  Two or more different elements that are chemically bonded
• Nucleus


  The center of an atom which contains protons and neutrons
• Molecule


  Two or more atoms that are chemically bonded
• Law of Conservation of Mass


  The total mass of the products formed in a reaction is equal to the total mass of the reactants
• State Symbol

  A symbol denoting what state a substance is in; solid (s), liquid (l), gas (g), aqueous solution (aq)
• Aqueous solution


  A solution that is dissolved in water; a solution where water is the solvent
• Mixture


  Two or more different elements that are not chemically bonded
• Filtration


  A way of separating mixtures; used when you need to separate a substance that is insoluble in the solvent (water) from a substance that is soluble in the solvent

  
• Crystallisation


  A way of separating mixtures; used when you need to separate a soluble solid from the solvent (water)

  
• Simple Distillation


  A way of separating mixtures; used when you need to separate a liquid from a solution

  
• Fractional Distillation


  A way of separating mixtures; used when the liquids in the mixture have similar boiling points

  
• Paper Chromatography


  A way of separating mixtures; used when you need to separate and identify substances from a mixture

  
• Atomic Theory


  The theory that everything was made up of tiny particles called atoms
• Plum Pudding Model


  J.J. Thomson's model of an atom; the model showed that the atom was a general sphere of positive charge, with electrons scattered around

  
• Rutherford Nuclear Atom

  Ernest Rutherford's model of an atom; the model showed that the postive charge of the atom was concentrated in the middle, and the negative charge was a cloud outside the middle positive charge

  
• Bohr's Model of the Atom


  Niels Bohr's model of an atom; the model showed that the electrons were orbiting the nucleus in shells

  
• Scientists who Developed the Model of the Atom

  Democritus - Atomic Theory

  John Dalton - Atoms were solid spheres and the simplest form of matter

  J. J. Thomson - Plum Pudding Model

  Geiger and Marsden - Firing alpha particles at a thin gold sheet

  Ernest Rutherford - Rutherford Nuclear Atom Model

  Niels Bohr - Electrons orbiting the nucleus in shells

  James Chadwick - Confirmed the existence of the neutron
• Proton


  A subatomic particle with a relative charge of +1 and a relative mass of 1 which is found in the nucleus
• Neutron


  A subatomic particle with a relative charge of 0 and a relative mass of 1 found in the nucleus
• Electron


  A subatomic particle with a relative charge of -1 and a neglible relative mass found orbiting the nucleus in shells
• Atomic/Proton Number


  The number of protons in an atom; also tells you how many electrons there are as all atoms have an equal number of protons and neutrons
• Mass Number


  The number of protons + neutrons in an atom