Question

The smell of hot sizzling food reaches you several meters away, but to get the smell of the cold food you have to go to close. Which property of matter does this activity show?
(A) Particles of matter have space
(B) Particles of matter are continuously moving
(C) Particles of matter attract each other
(D) None of the above

Answer 1

Hint: Try to recall that the kinetic energy of a particle is directly proportional to its absolute temperature. Higher the temperature more is the kinetic energy of a particle. Now, by using this you can easily find the correct option from the given ones.
Complete answer:
* It is known to you that it’s all about properties of state of the matter.
* The particles of hot sizzling food are at high temperature whereas the particles of cold food are at low temperature.
* We know that the kinetic energy of a particle is directly proportional to its temperature so the particles of hot sizzling food possess large kinetic energy whereas the particles of cold food possess less kinetic energy.
* So, due to the larger kinetic energy of the particles of hot food, their diffusion rate in air is higher and through air it reaches to us even though we are couple of meters away and alternatively, the diffusion rate of cold food is very low, thus one has to go close to the food to get its aroma.
Therefore, from above we can conclude that option D is the correct option to the given question.

Note:
* It should be remembered to you that rate of diffusion of a gas particle in air is directly proportional to its temperature and is inversely proportional to the molecular weight of gas.
* Also, you should remember that the rate of diffusion is independent of the size of particles that are diffusing.