When chemical substances such as perfume are let loose in a room, their particles mix with the particles of air. The particles of smelly gas are free to move quickly in all directions. They eventually spread through the whole room from an area of high concentration to an area of low concentration.
Atmosphere? I am not really sure what you are asking.
Answer:
b
Explanation:
analyze data, form hypothesis, perform experiment, draw conclusions
The answer is, 43 km/hr . Speed is,

So we will divide the given distance to the given time, so :