MAKING A PI

words by Dr. James D. Livingston

tune: Comin' Through the Rye (Traditional Scottish Tune)

Click here to play tune

When an atom meets an atom
And a bond they tie
Two s waves can make a sigma
p's can make a pi
Ev'ry AO mates an AO
To an MO supply
Both s and p can make a sigma
p's can make a pi

Pi bond in ethylene

(image courtesy of Prof. Brent Iverson)