Bubble Gum, Bubble Gum by Lisa Wheeler.
Children can enjoy examining the properties of a bubble (shape, interior, exterior, floating ability, elasticity, etc.) by using mild soap bubbles to do some of the activities suggested at some of several sites:
Steve Spangler’s Science Site.
Or http://www.cde.state.co.us/cdelib/ Do a search for bubblesforpreschoolers.