Chapter 1 : Matter in Our Surroundings : Class - 9 : Question and Answer (Part 1)

NCERT BOOK QUESTIONS AND EXERCISES Class - 9 Chapter 1 : Matter in Our Surroundings Question 1. Which of the following are matter ? Chair, air, love, smell, hate, almonds, thought, cold, cold-drink, smell of perfume Answer - Chair, air, smell, almonds, cold-drink, and smell of perfume are matter (because they occupy space and have mass). It should be noted that ‘smell’ is a matter because it is due to the presence of some volatile substances in air which occupy space and have mass. Question 2. Give reason for the following observations : The smell of hot sizzling food reaches you several metres away but to get the smell from cold food, you have to go close. Answer – The smell of food reaches us by the process of diffusion of gases (Released by the food) in to the air. The rate of diffusion of hot gases in to air is faster...