NCERT Class 9 Science (Chemistry) Chapter 1 – Matter in Our Surroundings (All in text and Exercise Questions solved)
Exercise-1.1-1.2 Page: 3 ( matter in our surroundings )
- Which of the following are matter?
Chair, air, love, smell, hate, almonds, thought, cold, lemon water, smell of perfume.
Solution: The following substances are matter:
Chair, Air, Almonds, Lemon water.
- Give reasons for the following observation:
The smell of hot sizzling food reaches you several meters away, but to get the smell from cold food you have to go close.
Solution: Particles in the air, if fueled with higher temperatures, acquire high kinetic energy which aids them to move fast over a stretch. Hence the smell of hot sizzling food reaches a person even at a distance of several meters.
- A diver is able to cut through water in a swimming pool. Which property of matter does this observation show?
Solution: The diver is able to easily cut through the water in the swimming pool because of the weak forces of attraction between water molecules. It is this property of water that attributes to easy diving.
- What are the characteristics of the particles of matter?
Solution: The characteristics of particles of matter are:
(a) Presence of intermolecular spaces between particles
(b) Particles are in constant motion
(c) They attract each other
