1.1.1 The Dalton Model of the Atom

• What are the key differences between the Rutherford nuclear model and the Thomson plum pudding model?

  • Rutherford model: Atoms have a dense, positively charged nucleus with electrons orbiting it
  • Thomson model: Atoms are a uniform, positively charged "pudding" with embedded negatively charged electrons
  • Rutherford model explains the results of the gold foil experiment, Thomson model does not
  • Rutherford model led to the discovery of the atomic nucleus, Thomson model did not
• What is Dalton's Atomic Theory primarily about?

  Fundamental idea in chemistry
• What does "simple ratios" mean in the context of Dalton's Atomic Theory?

  Atoms combine in simple proportions
• What aspect of atomic structure did Dalton's model fail to account for?

  Internal structure of protons, neutrons, electrons
• What was the main contribution of Dalton's Atomic Theory?

  It was revolutionary for its time
• Who proposed the nuclear model of the atom in 1911?

  1. Rutherford
• What are the key points of Dalton's Atomic Theory?

  • All matter is made of atoms
  • Atoms of the same element are identical
  • Atoms cannot be created or destroyed
  • Atoms combine in simple ratios
• Who proposed the quantum model of the atom in 1926?

  Erwin Schrodinger
• What are the key points summarizing Dalton's postulates?

  • Composition: All matter is composed of atoms.
  • Identity: Atoms of the same element are identical.
  • Conservation: Atoms cannot be created or destroyed in reactions.
  • Combination: Atoms combine in simple ratios to form compounds.
• What are the key features of the Bohr model of the atom?

  • Electrons orbit the nucleus in fixed energy levels
  • Electrons can only absorb or emit energy in discrete amounts when moving between levels
  • The angular momentum of electrons is quantized
  • The model explains the hydrogen atom's discrete emission spectrum
• What is the first postulate of Dalton's Atomic Theory?

  All matter is made up of atoms.
• What happens to atoms during chemical reactions according to Dalton's theory?

  They rearrange but are not created or destroyed.
• In what manner do atoms of different elements combine?

  In simple, whole-number ratios
• What number did Dalton assign to hydrogen?

  1
• What tiny pieces do atoms contain?

  Electrons and protons
• What type of atomic model was proposed by N. Bohr in 1913?

  Planetary model
• What did Dalton's Model lay the foundation for?

  Modern atomic theory
• How did Dalton represent heavier elements?

  By giving them bigger numbers
• How are atoms of a given element characterized according to Dalton's theory?

  They are identical in mass and properties
• Who proposed the solid sphere model of the atom in 1807?

  1. Dalton
• What did Dalton create for each element?

  Special pictures
• What did Dalton's atomic model depict atoms as?

  Solid spheres
• What analogy did Dalton use to describe atoms?

  Like tiny billiard balls
• What is the title of the image?

  Elements
• Who proposed the first atomic model in 1807?

  Dalton
• What is the conservation of atoms in Dalton's Atomic Theory?

  Atoms cannot be created or destroyed
• What are atoms?

  Tiny particles that make up matter
• What was the significance of Dalton's atomic model?

  • First atomic model proposed
  • Atoms as solid spheres
  • Explained chemical reactions
  • Atoms combine in simple ratios
• How did Dalton describe atoms in his model?

  As indivisible and uniform in size
• What are the key contributions of Dalton's Model?

  • Atomic Theory: Atoms as indivisible particles
  • Relative Atomic Weights: Weights assigned relative to hydrogen
  • Symbols for Elements: Unique symbols for each element
• What did Dalton assign to elements based on hydrogen?

  Atomic weights
• How does the quantum model of the atom differ from the Bohr model?

  • Electrons exist in probabilistic "clouds" rather than discrete orbits
  • Electron energy levels are described by quantum mechanical wave functions
  • Electrons can occupy any energy level, not just specific discrete levels
  • The model accounts for the wave-particle duality of electrons
• What are the names of the chemical elements shown in the table?

  • Hydrog.
  • Azote
  • Carbone or charcoal
  • Oxygen
  • Phosphorus
  • Sulphur
  • Magnesia
  • Lime
  • Soda
  • Potash
  • Strontites
  • Barytes
  • Iron
  • Zinc
  • Copper
  • Lead
  • Silver
  • Platina
  • Gold
  • Mercury
• What does it mean that atoms of a given element are identical?

  They have the same mass and properties.
• What is the significance of using unique pictures for elements in Dalton's model?

  • Helps in easy identification of elements
  • Provides a visual representation
  • Aids memory retention
• How does the Bohr model build upon and improve the Rutherford nuclear model?

  • Bohr model explains the discrete emission spectrum of hydrogen, which the Rutherford model could not
  • Bohr model introduces the concept of quantized electron energy levels, which the Rutherford model lacked
  • Bohr model provides a more detailed description of electron behavior and the structure of the atom
  • Bohr model represents a step towards the modern quantum mechanical model of the atom
• What type of atomic model was proposed by J.J. Thomson in 1897?

  Plum pudding model
• What patterns or relationships can you observe in the relative weights of the chemical elements?

  • The relative weights range from 1 (Hydrog.) to 167 (Mercury)
  • The weights tend to increase as you go down the list, with some exceptions
  • There are groups of elements with similar weights, e.g. Zinc and Copper both have a weight of 56
  • The heaviest elements are the metals like Gold, Platina, and Mercury
• What are some of Dalton's calculated atomic weights compared to modern weights?

  • Oxygen: Dalton's weight 8, Modern weight 16
  • Copper: Dalton's weight 64, Modern weight 63.5
  • Gold: Dalton's weight 190, Modern weight 197
• Why was assigning weights to elements important?

  It helped understand element ratios in compounds