History of atoms

• Who created the idea of atoms?

  John Dalton
• In what year did John Dalton propose his atomic theory?

  1805
• What concept did the ancient Greeks contribute to atomic theory?

  The idea of atoms
• Who discovered electrons in atoms?

  JJ Thompson
• What did students discover about the structure of the atom?

  The nucleus
• In what year did Neils Bohr describe electrons in shells?

  1914
• Who discovered neutrons in the nucleus?

  James Chadwick
• In what year did James Chadwick discover neutrons?

  1932
• What are the key developments in atomic theory from the 19th to 20th century?

  • John Dalton (1805): Proposed atomic theory
  • Ancient Greeks: Introduced the concept of atoms
  • JJ Thompson: Discovered electrons in atoms
  • Students: Identified the nucleus
  • Neils Bohr (1914): Described electrons in shells
  • James Chadwick (1932): Discovered neutrons in nucleus