Atomic Models - CGP

• What are atomic models useful for in chemistry?

  Understanding various ideas in chemistry
• How has the accepted model of the atom changed over time?

  It has evolved based on new evidence
• Who described atoms as solid spheres?

  John Dalton
• What did Dalton say about different elements?

  Different spheres make up different elements
• What did J. J. Thomson conclude about atoms in 1897?

  Atoms contain negatively charged electrons
• What was the name of Thomson's atomic model?

  The plum pudding model
• What experiment did Rutherford conduct in 1909?

  The gold foil experiment
• What did Rutherford expect from the plum pudding model during his experiment?

  Most alpha particles to be slightly deflected
• What did Rutherford's experiment reveal about the atom?

  Most of the atom is empty space
• What is the nuclear model of the atom proposed by Rutherford?

  A tiny nucleus surrounded by electrons
• What did scientists realize about electrons in Rutherford's model?

  They would spiral into the nucleus
• What are the two basic principles of Bohr's model?

  Electrons exist in fixed orbits and shells
• What happens when an electron moves between shells in Bohr's model?

  Electromagnetic radiation is emitted or absorbed
• Why did the Bohr model fit observations from experiments?

  It explained the frequencies of emitted radiation
• What did scientists discover about electrons in a shell after Bohr's model?

  Not all electrons had the same energy
• What is the refined Bohr model known for?

  Including sub-shells for better accuracy
• Why is the refined Bohr model still widely used?

  It is simple and explains many observations
• What is the most accurate model of the atom today based on?

  Quantum mechanics
• Why do scientists use different atomic models?

  Based on relevance to their investigations