P1

• Gas -> solid

  Deposition
• Law of conservation of mass

  Mass is conserved in every change of state because the number of atoms does not change
• Size of an atom

  1x10^-10m
• What did Dalton suggest about the atom?

  All atoms in an element are the same

  The atoms in one element are different from the atoms in all other elements
• What did Thompson suggest about the atom?

  The atom was positively charged with negative electrons moving around inside it
• What did Rutherford suggest about the atom

  The positive charge was concentrated at the centre of the atom, called the nucleus
• What did Bohr suggest about the atom?

  Electrons were arranged in energy levels around the nucleus