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atomic structure, Atomic structure - Coggle Diagram

- - - - elements are the simplest substances
      - there are about 100 different elements
      - each element is made up of very tiny particles called atoms, and each element is made up of just one particular type of atom, which is different to the atoms in any other element
    - - atoms are the building blocks that makes up matter
      - john Dalton had the first ideas about the existence of atoms over 200 years ago
      - it is only recently that special microscopes (called electron microscopes) have been invented that can actually see atoms
  - - - he suggested that elements existed in orbit
      - a later discovery found that the nuclear was made of individual positive particles called protons
      - his experimental findings agreed with his calculations and therefore was accepted as Part of the nuclear model
    - - chadwick discovered the neutrally charged, the neutron
    - - john Dalton suggested that the tiny particles called atoms existed in his theory
      - he said that these were like tiny spheres that could not be divided
    - - this model showed that mass is concentrated in the nucleus and that the nucleus repelled the alpha particles showing the nucleus must be of a positive charge
      - Rutherford tested the plum pudding model by firing alpha particles at thin gold foil
      - this experiment led to the nuclear model of the atom
      - most of the alpha particles went straight through, however a small number of alpha particles reflected back
    - - The plum pudding model was proposed by JJ Thomson.
      - in this model the atom was suggested to be a ball of positive charge with negative particles distributed randomly within the ball of positive charge