This little activity goes along nicely with NGSS MS-PS1-4 and MA 8 MS-PS1-4 by demonstrating that particles move farther apart when heated. I use it as an easy take home laboratory and count it as a homework assignment, but it could easily be modified to be done in class using ice instead of a freezer. Students place a bottle in the freezer, remove it, put a coin on the top, and observe thermal expansion in action! Then then fill in blanks explaining what happens in terms of particles. Each sheet contains 2 assignments, so you make half the copies and cut the papers in half. Assignment contains instructions and quick concept review.