Iron, sulfur, and iron sulfide are examples of solids that can be found in a classroom, whether visible or not. Liquids and gases examples were also requested. A fourth state of matter, plasma, is mentioned as an extension. The document discusses a model of iron and sulfur atoms being stuck together after heating to form iron sulfide, providing evidence that heating changes their physical state by bonding the atoms.

1. 10 October 2010 4.2 CSI Particles List 3 (can you do 5?) examples of solids, liquids and gases from the classroom. You may or not be able to see them! Extension: What is the other famous state of matter?

2. What is a model?

3. Model or not model?

9. Iron Sulfur Iron sulfide

10. Considering the evidence Before heating, the iron and sulfur atoms are not stuck together. After heating, the iron and sulfur atoms are stuck together in a compound What evidence is there that heating changes the iron and sulfur What evidence is there that the iron and sulfur atoms are stuck together after heating? Extenstion: What do the atoms look like at each stage of the experiment?