Consider a pot of boiling water on top of a stove. There is initially a lid on the pot that doesn't let any matter escape from the pot, and the pot is being heated by a flame below.

a$)$ Draw a system boundary that contains all the matter in the pot in this initial state. Is this an open or a closed system? Draw any important mass$/$energy interactions between the system and the surroundings as arrows that indicate the directions of these mass$/$energy flows.

b$)$ Now imagine that the lid of the pot is suddenly lifted and that your system geometry remains the same $($i$.$e$.,$ the bounds of your system don't move$).$ Is this an open or a closed system? Draw any important mass$/$energy interactions between the system and the surroundings as arrows that indicate the directions of these mass$/$energy flows.