Bohr's Model of the Atom | Physics for Grade 10 PDF Download

Introduction

• In 1913 the Danish Physicist, Niels Bohr, came up with an improved model of the atom
• He used the nuclear model to create his model
• In the Bohr model of the atom:
  • Electrons orbit the nucleus at different distances
  • The different orbit distances are called energy levels
  • Up to 2 electrons orbit in the first energy level
  • Up to 8 electrons can orbit in the second energy level
  • Up to 8 electrons can orbit in the third energy level
    
    In the Bohr model of the atom electrons orbit in distinct energy levels, which are at different distances from the nucleus

Successes of the Bohr Model

• The Bohr model became the accepted model because:
  • It was able to explain the findings from different experiments better than the nuclear model of the atom
  • It was able to explain the processes of absorption and emission of electromagnetic radiation
  • Theoretical calculations made using the Bohr model agreed with experimental results

Solved Example

Example: The Bohr model of the atom replaced the nuclear model of the atom.Describe the main advantage of the Bohr model over the nuclear model.

Step 1: Describe the difference between the two models

• The nuclear model describes the atom as having a positively charged nucleus with electrons orbiting it
• The Bohr model is similar to the nuclear model in that it describes the atom as having a positively charged nucleus but the electrons orbit at specific distances in distinct energy levels

Step 2: Describe why the Bohr model was better

• The Bohr model could explain the findings of experiments better than the nuclear model