Answer:
The aroma of the popcorn spreads throughout the room gradually due to the presence of air.
Step-by-step explanation:
The popcorn bag releases an aroma when opened. This aroma then travels through the air due to which the aroma spreads throughout the room.
Note:
If the room was closed, the aroma will remain inside the room. If the room was open, the aroma will also spread beyond the room due to the presence of air.