Today, we started to wrap up our mass lab with a board meeting. Students shared their groups data for each station and then had to make histograms and particle model explanations. One group put forward the interesting and plausible explanation that hear increases the size of particles adding mass when we heated steel wool.
Some said there was a color change and thought it was something else. I asked them to come up with an experiment to compare heat and mass. So we heated a piece of copper I had and saw no mass difference. With our new data, they talked it over and updated their model to include oxygen. This also lea to a discussion if we could call it burning when something ended up with more measurable mass.
All in all a really great discussion! Now we have four more to go!