Editing Marshmallow Smashies (section)

== Why This Works == 

This introduces ''Air Pressure'', which is the force of the air applied on everything around it. Air pressure is pretty strong, but we don't normally notice it because our bodies push back against it. Marshmallows also push back, because they have a lot of little air pockets in them. When we put the marshmallows in the vacuum flask and sucked the air out, there was a lot less air pushing on them. We put the marshmallows in a ''Vacuuum'', or an area with a lot of empty space, including no air! The air inside the marshmallows then was able to take up a lot more space, which caused them to expand. However, the marshmallow could only expand so far until the bubbles started to pop! The marshmallows then lost a lot of the air inside them, which caused them to shrink in the vacuum, and less air inside them meant that they could not push back as much. This is why, when we let the air back in, the marshmallows were smashed!