States of Matter!
Today we explored the changes that occur between the different forms, or states of matter. Matter can transition between states by adding or removing heat (energy). Most of us are familiar with the liquid, solid, and gas states of matter but have you ever thought about how they are defined? Solids maintain a constant shape and volume; liquids maintain a constant volume but take on the shape of the container; gases expand to fill the container and so have neither a constant shape nor a constant volume.
We also investigated the changes that occur when matter transitions from one state to another. We all know that when a liquid transitions to a gas, it is called vaporization (or evaporation), and changes between solids and liquids are referred to as melting and freezing, but some of the change terms were new, such as deposition (gas to solid). Through demonstrations with dry ice (the solid state of carbon dioxide), the students were able to observe one particularly exciting transition in action: sublimation (solid to gas).
We studied sublimation by adding dry ice to water. The warmth of the water causes the dry ice to sublimate rapidly, releasing clouds of white vapor (carbon dioxide gas) that quickly sinks and dissipates. This was great fun to investigate and allowed the students to see all three states of matter (solid, liquid and gas) in a single cup.
Check out this video on how to make dry ice bubbles!