The boys were given a mystery solid and a mystery liquid to observe carefully. We came up with several different words to describe them, and we listed them on a whiteboard, and then we made predictions on what would happen if we mixed them, and they talked about dissolving. Once I poured the liquid into their cups, they carefully observed what happened. We decided that dissolving was when a solid seems to disappear in a liquid. We then talked about whether they thought that the solid was gone, still in the liquid, or had gone somewhere else. We talked about how one way of finding out if the solid is still in the liquid is to see if the liquid changes. If it changes, then maybe the solid is still in there, causing it to change. We will leave the cups overnight and see if there are any changes.