Swinging Electrons (Demonstration)
(Reference: Borislaw Bilash II, George R. Gross & John K. Koob A Demo a Day:  A Year of Chemical Demonstrations, Published by :  Flinn Scientific Inc.)
 

Electron Configuration    :     Paramagnetism     :     Orbitals
 

Purpose:
Illustrate paramagnetic and diamagnetic differences due to the unfilled and filled valence shells.
 

Safety:
Copper sulfate is a skin irritant and toxic by ingestion and inhalation.  Zinc and manganese sulfates are moderate skin and mucous membrane irritants.  Wear goggles and gloves.
 

Materials:
8 test tubes
Thread
Calcium sulfate
2 ring stands with clamps
Manganese sulfate
Horizontal bar
Cupric sulfate
Powerful magnet
Zinc sulfate
 

Procedure:
Prepare saturated solutions of each and place into the test tubes.  Place each corresponding solid metal sulfate in the other four test tubes.  Label each tube.  Suspend each tube from the horizontal bar.  Bring magnet close to each.  Those containing manganese and copper (particularly the solids) will be attracted.
 

Explanation:
Electron configurations:

Ca2+   1s22s22p63s23p6   (diamagnetic)
Zn2+            1s22s22p63s23p64s03d10   (diamagnetic)
Cu2+            1s22s22p63s23p64s03d (paramagnetic)
Mn2+        1s22s22p63s23p64s03d  (paramagnetic)
 
The compounds with completely filled valence shells will not attract the magnet, like calcium ion and zinc ion (these are said to be diamagnetic).  Those with unfilled valence shells will attract the magnet (paramagnetic).
 

Clean-up:
Save tubes and use year to year.
 
 

Ginger Chateauneuf, 2000.
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