Electron Configuration

1. Electron Configuration Chapter 5: Atomic Structure Section 5.3

2. Quantum States and Orbitals • Quantum state = a specific combination of values of variables such as energy and position that is allowed by quantum theory. • We group electrons into different quantum states to describe their electron arrangement.

3. Quantum States and Orbitals • There are 4 shapes associated with quantum states: s, p, d, and f.

4. Orbitals • Orbitals hold electrons, and show the area in which the electrons can be found. • S orbitals can hold 2 electrons • P orbitals can hold 6 electrons • D orbitals can hold 10 electrons

5. Electron Configurations • Electron configuration = a description of which orbitals contain electrons for a particular atom.

6. Finding Electron Configuration • The complete list of orbitals and the order in which they fill for all of the currently discovered elements is: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p • The order tells a chemist exactly how the electrons are structured in an atom.

7. How to find electron configuration:

9. Book Work • Read pages 148-159. • Answer questions 43, 49, 52-54, 56, 58, 62. • Find the electron configurations for Calcium, Bromine, and Tungsten.

10. Subshells

11. Arrow Notation • We have learned the long method of writing out electron configuration. • We can also write electron config. using the box and arrow method.

12. Hund's rule of maximum multiplicity • When more than one orbital of equal energies are available then the electrons will first occupy these orbitals separately with parallel spins. • The pairing of electrons will start only after all the orbitals of a given sub level are singly occupied.

13. For example, the three electrons that are filled into the three 'p' orbitals can be represented in two different ways:

14. Nobel Gas Notation (Short-Hand Method)