Here's a very EASY, SAFE lab to do that will get your kids to realize that temperature does NOT increase during melting or during boiling. It's fascinating to watch students predict the shape of a temperature vs. time graph of ice as it heats up to 100 degrees Celsius. It's even MORE exciting when this lab proves them wrong! Your students will be engaged and invested in understanding WHY the temperature is constant during a state change. At this point, you can lead them in the direction of intermolecular forces.
Just give your students some basic lab equipment, some ice, and a timer! These handouts will do the rest.
This product is in WORD format, so it's easily edited to suit your needs. It includes a student handout and lab procedures.