Blogs

I tend to enjoy acid base titrations for several reasons.  First, students get to work with burettes, acids, bases and they see a nice "color change" when they reach an endpoint. Many times, students who tend to struggle with pen and paper testing excel at the "hands-on" approach. Titrations also dovetail well with stoichiometry which provides a nice review of information closer to the end of the year.

When describing abstract concepts like chemical bonding, it always seems to feel far too easy for both teachers and students to resort to the “wants” and “needs” of atoms. After all, we understand what it means to want, need, or like something, so it often feels appropriate (and easier) to use a relatable metaphor or subtly anthropomorphize these atoms to accommodate our students’ current reasoning abilities. While predicting the types of bonds that will form and the general idea behind how atoms bond can be answered correctly using such relatable phrases or ideas, the elephant in the room still in remains—do our students really understand why these atoms bond? 

I think this experiment provides a fantastic vehicle to involve students of all ages in small, hands-on and exploratory research projects. Like many others, my students and I have investigated various aspects of this interesting fountain.

Are you familiar with the dynamic density bottle experiment? This interesting experiment was invented by Lynn Higgins, and is sold by various science supply companies. Two immiscible liquids (usually salt water and isopropyl alcohol) and two different types of plastic pieces are contained within a dynamic density bottle. The plastic pieces display curious floating and sinking behavior when the bottle is shaken. 

Have you considered having your students make solar cells? If your AP kids can understand batteries, solar cells are a logical next step. I usually do independent projects after AP along with final presentations, but I stumbled upon this activity the other day and my mind exploded in excitement and thought I would share. In the future, I would definitely do this with my students!