Configuration (pages 117 – 122)
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?
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:
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.
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
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?