Title: Electron

Configuration (pages 117 – 122)

Objective: Questions:

Notes: Subshells in Atoms: 1. Electrons are arranged into shells, and the number of shells in an atom is the same as the period the element is located. 1 2 3 4 5 6 7

a. i. 2. Each shell is further divided into subshells. These subshells are called s,p,d and f. a. Each subshell has a max capacity of electrons. i. b. Aluminum: 1. How many total electrons are there is aluminum? 2. What shells are they in? 3. How many valence e- does Al have? Which subshell are they in? 4. How many electrons are in the 3s subshell? In the 3p subshell?

Answers:

Electron configuration: 3. Electron configuration is a shorthand to keep track of the electrons in an atom. a.

b. c. The sequence in which e- are filled is: Summary:

   

Questions:

Notes: d. EX: Li: 1s2 2s1 e. EX: f.

Write the electron configuration for sulfur.

§ §

The superscripts add to 3, which is the # of e- in Li.   There are 2 electrons in the 1s orbital and 1 e- in the 2s orbital.  

EX:

Answer: Connecting the Periodic Table to Electron Arrangements 4. You can use the periodic table to determine electron configuration and outer shell. (Remember: the number of Any element in the green region will have their outer most electron (s) in a p subshell. EX: Argon’s e- configuration:

a. When you get to the

period, you need to add the d subshell into the

configuration. EX:

is in the 4th period, to the electron configuration

is: Write the electron configuration for cobalt, Co.

Answer: Noble Gas Shorthand 5. In order to make the writing of electron configuration a little easier, you can use the noble gas at the end of the previous period to show all the filled subshells. a. EX:

Selenium: What is the electron configuration (long)? Write the e- configuration using noble gas shorthand. In what subshells are selenium’s valence electrons?

Summary: