Chapter 5 Electrons In Atoms 5.1 Revising the Atomic Model 5.2 Electron Arrangement in Atoms 5.3 Atomic Emission Spectra and the Quantum Mechanical Model Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.
What did Bohr propose in his model of the atom? Energy Levels in Atoms Energy Levels in Atoms What did Bohr propose in his model of the atom? Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.
Limitations of Rutherford’s Atomic Model Energy Levels in Atoms Limitations of Rutherford’s Atomic Model It explained only a few simple properties of atoms. It could not explain the chemical properties of elements. For example, Rutherford’s model could not explain why an object such as the iron scroll shown here first glows dull red, then yellow, and then white when heated to higher and higher temperatures. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.
Energy Levels in Atoms The Bohr Model In 1913, Niels Bohr, a young Danish physicist and a student of Rutherford, developed a new atomic model. Bohr proposed that an electron is found only in specific circular paths, or orbits, around the nucleus. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.
Each possible electron orbit in Bohr’s model has a fixed energy. Energy Levels in Atoms The Bohr Model Each possible electron orbit in Bohr’s model has a fixed energy. The fixed energies an electron can have are called energy levels. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.
Energy Levels in Atoms The Bohr Model The rungs on this ladder are somewhat like the energy levels in Bohr’s model of the atom. A person on a ladder cannot stand between the rungs. Similarly, the electrons in an atom cannot exist between energy levels. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.
Energy Levels in Atoms The Bohr Model The rungs on this ladder are somewhat like the energy levels in Bohr’s model of the atom. The energy levels in atoms are unequally spaced, like the rungs in this unusual ladder. The higher energy levels are closer together. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.
The Quantum Mechanical Model We now know that electrons aren’t on rings but can be found within a certain volume of space surrounding the nucleus. This can be represented as a fuzzy cloudlike region. The cloud is more dense where the probability of finding the electron is high. Electron cloud Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.
How do sublevels of principal energy levels differ? Atomic Orbitals Atomic Orbitals How do sublevels of principal energy levels differ? Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.
Different atomic orbitals are denoted by letters. The s orbitals are spherical. The p orbitals are dumbbell-shaped. The d orbitals are flower shaped The f orbitals are asterix shaped Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.
Atomic Orbitals Different atomic orbitals are denoted by letters and the size is dependent on the energy level Kinetic Art 5.1 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.
END OF 5.1 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.