Electron Configuration Writing Electron Configurations Using the atomic

Electron Configuration

Writing Electron Configurations Using the atomic number as the total number of electrons you can write the electron configuration for all of the neutral elements. The number of electrons in each sublevel is written as an exponent.

Energy Relationship of Sublevels The Aufbau principle states that an electron occupies the lowest energy orbital that can receive it. Energy levels overlap so the diagram shows the order of the sublevels.

Electron Configuration Periodic Table

Write the electron configuration for: • Magnesium #12 Mg 1 s 2 2 p 6 3 s 2 • Gallium #31 Ga 1 s 2 2 p 6 3 s 2 3 p 6 4 s 2 3 d 10 4 p 1 • Bromine #35 Br 1 s 2 2 p 6 3 s 2 3 p 6 4 s 2 3 d 10 4 p 5

Use the periodic table to write the noble gas notations for the following atoms. (Shorthand electron configuration) Example 1: Nitrogen, 7 electrons [He] 2 s 2 2 p 3 Example 2: Phosphorus, 15 electrons [Ne] 3 s 2 3 p 3 Example 3: Cerium, 58 electrons [Xe] 6 s 2 4 f 2

Isoelectronic- when two elements share the same electron configuration § Metals lose electrons and nonmetals gain electrons to look like noble gas electron configurations. § So, when cations(+) and anions(-) are formed, they will have the same electron configuration as each other at times. § Na+ is 1 s 2 2 p 6 and F- 1 s 2 2 p 6. § The same thing happens to Ca 2+ 1 s 2 2 p 6 3 s 2 3 p 6 and Cl- 1 s 2 2 p 6 3 s 2 3 p 6. § When an ion is created, just add or remove electrons from the neutral configuration of the element.