Electronic Configuration

Electron Configuration and Quantum Number Problems

1) What are the four quantum numbers and what do they indicate?

2) If an element possesses n = 3, what are the possible l values?

What are the possible m values?

3a) Write out the electron configuration for Na, S, Mo, Ne, and Ce. (The whole thing!!!)

3b) Draw the Lewis dot diagram.

3c) How many valence electrons does each of those elements have?

3d) What is the oxidation number for each of those elements?

4) What is the charge of noble gases? Why? Where do I find noble gases on the periodic table?

5) What is the charge of halogens? Why? Where do I find them on the periodic table?

6) What is the charge of alkaline earth metals? Why? Where do I find them on the periodic

table?

7) Why are transition metals in transition? Why do you want a list of their charges for the test?

8) Where are the metalloids?

ANSWERS

1) What are the four quantum numbers and what do they indicate?

n is the principal quantum number and is the energy level

n describes the relative electron cloud size

l is the sublevel; it describes the shape of the electron cloud

m, is the orbital; it describes the orientation in space of each orbital

s is the direction of the spin of the electron

2) If an element possesses n = 3, what are the possible l values?

What are the possible m values?

if n = 3, then there are 3 sublevels

the sublevels would be s=1, p=2, and d=3

m would be the orbitals

s has one orbital; 0

p has 3 orbitals; -1, 0 1

d has 5 orbitals; -2, -1, 0, 1, 2 these would be the possible m values

3a) Write out the electron configuration for Na, S, Mo, Ne, and Ce. (The whole thing!!!)

3b) Draw the Lewis dot diagram.

3c) How many valence electrons does each of those elements have?

3d) What is the oxidation number for each of those elements?

3e) What are the quantum numbers for each of those elements?

-3 -2 -1 0 1 2 3

Na 1s2 2s2 2p6 3s1 Na . 1 valence electron +1 oxidation number

3s1 n=3 L = 1 m = 0 s = +1/2