A perfume bottle is opened in one corner of a room. After a few minutes, people at the opposite corner can smell the perfume. Which two factors explain why the perfume spreads across the room?

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Question

A perfume bottle is opened in one corner of a room. After a few minutes, people at the opposite corner can smell the perfume. Which two factors explain why the perfume spreads across the room?

Accepted Answer

Perfume molecules have kinetic energy and move randomly in all directions — Award 1 mark for recognizing that particles have kinetic energy and move randomly. B is incorrect — diffusion does not depend on molecular attraction. C is incorrect — air pressure does not selectively push perfume molecules; diffusion occurs down a concentration gradient. D is incorrect — diffusion occurs in all directions due to random movement, not because molecules float.

Answer

Air pressure pushes perfume molecules across the room

Answer

Perfume molecules are lighter than air and float upwards then across

Answer

Perfume molecules have kinetic energy and move randomly in all directions

Answer

Perfume molecules are attracted to oxygen molecules in the air

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