Atomic structure

    Cards (76)

    • what is the radius of an atom?
      around 1 x 10 ^(-10) metres­­­­­­­­­­­­­­­
    • what charge does the nucleus have?
      positive
      the nucleus contains protons and neutrons
      protons have a charge of +1 and neutrons have no charge
    • what charge do electrons have?
      -1
    • what is the overall charge of an atom?
      neutral
      they have an equal number of protons and electrons resulting in no overall charge
    • what part of an atom contains the mass?
      the nucleus
    • the radius of the nucleus is less than...
      1/10,000 of the radius of an atom
    • electrons are arranged...
      at different distances from the nucleus
      in different energy levels
    • the energy levels of an electron may change when the atom emits or absorbs electromagnetic radiation:

      absorbing electromagnetic radiation moves electrons to a higher energy level, further from the nucleus
      electromagnetic radiation is emitted when an electron drops to a lower energy level
    • positive ions
      when an atom loses one or more of its outer electrons
    • negative ions
      when an atom gains one or more electrons
    • atomic number
      number of protons
    • mass number
      the total number of protons and neutrons
    • isotopes
      atoms with a different number of neutrons
      this changes the mass number however the atomic number remains the same
    • who discovered the electron?
      j.j. thompson
    • when were electrons discovered?
      1897
    • before electrons were discovered atoms were though of as...
      tiny solid spheres that could not be divided
    • what is the plum pudding model?
      a model that shows the atom as a ball of positive charge with negative electrons embedded in it, like plums in a pudding
      the first scientific model of the atom with internal structure
    • who created the plum pudding model?
      j.j. thompson
    • who carried out rutherford's experiment?
      geiger and marsden
    • when was rutherford's experiment carried out?
      1905
    • what did rutherford's experiment involve?
      bombarding thin gold foil with alpha particles
    • what happened to the particles?
      most particles did pass through, some were deflected and some were reflected back
    • what did the deflected particles show?
      that contrary to the plum pudding model which suggested charge was spread out, the gold foil had concentrations of charge
      these alpha particles had come close to a concentration of charge
    • what did the reflected particles show?
      they must have been repelled by the same charge that the alpha particles carried
      the repelling charge must have been much heavier than the alpha particle or the alpha particle would have passed through
    • what was the conclusion of the rutherford experiment?
      the mass of the atom was concentrated in a central nucleus, which was positively charged
      the electrons surround this nucleus
    • who created the nuclear model?
      ernest rutherford
    • who designed the gold foil experiment?
      ernest rutherford
    • what did niels bohr suggest?
      electrons orbit the nucleus at specific distances
    • what did later experiments lead to?
      the idea that the positive charge in the nucleus can be divided into a whole number of smaller particles, each with the same amount of positive charge
      these particles were named protons
    • when did james chadwick carry out his experiments?
      1932
      20 years after the nuclear model was accepted
    • what did the experiments of james chadwick show?
      that there was another particle within the nucleus (neutron)
      this led to further refinement of the nuclear model
    • who created the solid sphere model and when?
      john dalton
      1803
    • who created the plum pudding model and when?
      j.j. thompson
      1904
    • who created the nuclear model and when?
      ernest rutherford
      1911
    • who created the planetary model and when?
      niels bohr
      1913
    • who created the quantum model and when?
      erwin schrodinger
      1926
    • name the six main scientists involved in atomic theory
      john dalton
      j.j. thompson
      ernest rutherford
      niels bohr
      james chadwick
      erwin schrodinger
    • name the five atomic models
      solid sphere model
      plum pudding model
      nuclear model
      planetary model
      quantum model
    • what model is currently the most widely accepted as the most accurate model of the atom?
      the quantum model
    • unstable nuclei...
      give out radiation in order to become more stable