Valence

Mr. Henderson was buying generic decaf,

his tracksuit pilled at the elbows

and a grease stain near the zipper.

He was arguing about a fifty-cent coupon

for coffee that probably tastes like dirt.

His hand shook as he dug for a nickel,

fingernails yellowed and thick.

I stood behind him with a gallon of milk

remembering when he seemed like a giant

standing in front of a chalkboard

explaining how atoms want to be whole.