(1) start

• state the masses of the sub-atomic particles

  proton - 1

  neutron - 1

  electron - almost 0
• State the relative charges of the sub-atomic particles

  proton - +1

  neutron - 0

  electron - -1
• what did the gold foil experiment prove

  that atoms have a small dense nucleus in the centre with a positive charge
• what is the atomic number of an atom

  the number of protons of an atom
• what is the mass number of an atom

  the number of protons + neutrons in an atom
• what did chadwick discover

  the existence of neutrons
• what did bohr's experiments show

  that electrons are in specific shells (energy levels)
• what are isotopes


  atoms of the some element, with the same number of protons but different number of neutrons
• what does the group number tell you about an element

  the number of electrons in the outer-shell
• what does the period number you about an element


  how many electron shells the element has
• who discovered the plum pudding

  JJ Thompson
• why did Mendeleev put some elements in groups

  because they had similar properties
• who did the alpha scattering experiment

  E. Rutherford
• Write the electronic structure of the element in group 4, period 3 

  2,8,4
• why did mendeleev leave gaps in his periodic table

  as he knew some elements hadn't been discovered yet
• what is a molecule


  2 or more atoms covalently bonded together
• what is an element


  is a group of atoms or molecules where all the atoms are identical
• what is a compound


  2 or more different atoms are chemically bonded together
• what happens to the reactivity as you go down group 1

  the reactivity increases as you go down group 1
• what happens to the reactivity as you go down group 7

  the reactivity decreases as you go down group 7