Answer:
Because a fire requires oxygen from the atmosphere to burn.
Explanation:
An open system is when the fire needs the air to burn and also allow the smoke to escape or be released without the need to be "guided" or drive along a made path such as a chimney or through a stack. This process ensures that no smoke is retained or confined in a closed space.
Burning of wood involves a great deal of smoke being released by the burnt wood. So, for the smoke to be released freely, the act of burning in an open space facilitates easier means of dispersing the smoke and not be harmful to the persons/ living things nearby. If wood burning is done in a closed space, it will only suffocate the ones inside the room, making it difficult for fresh air to facilitate easy burning and will require a chimney for the smoke to be released.
Thus, <u>a wood-burning fireplace represents an open system as fire requires oxygen from the atmosphere to burn and also disperse the smoke easily without the need for a chimney or a stack.
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