In this animated object, learners examine how changes in pH affect the salt bonds in strands of hair.
In this animated object, students observe how ATP energy is used to move substances across the cell membrane from an area of lower concentration to an area of higher concentration and when something too large needs to get in or out of a cell.
In this screencast, learners examine the kinds of physical and chemical changes that occur in substances.
By Deb Simonson