CHM - Ch. 2

• _____ came up with the Atomic Theory.

  Dalton
• The law of ________________ stated all compounds have a definite composition. Meaning that the relative number of atoms of each element in the compound is the same in any sample.

  constant composition
• The law of _________________ stated the total mass of substances present at the end of a chemical process (reaction) is the same as the mass of substances present before the process took place.

  conservation of mass
• Postulates of Dalton’s theory (1)

  Each element is composed of extremely small particles called atoms.
• Postulates of Dalton’s theory (2)

  All atoms of a given element are identical, but the atoms of one element are different from the atoms of all other elements.
• Postulates of Dalton’s theory (3)

  Atoms are neither created nor destroyed in chemical reactions.
• Postulates of Dalton’s theory (4)

  A given compound always has the same relative number and kind of atoms.
• ________ particles were discovered 100ish years later after Dalton’s death.

  Subatomic
• The Electron (cathode rays) was discovered by _________.

  JJ Thompson
• __________ discovered the charge of the electron in 1909 with his oil drop experiment.

  Robert Millikin
• The proton was discovered by _____________.

  Ernest Rutherford
• Radioactivity was discovered by ______________.

  Marie and Pierre Curie
• _________ is the spontaneous emission of high-energy radiation by an atom.

  Radioactivity
• Alpha particles are _______ charged.

  positively
• Beta particles are ________ charged.

  negatively
• Gamma rays are _______.

  uncharged