Activity 1.4 Explanation NCERT Science Class 9 Matter In Our Surroundings
Activity 1.4 asks us to put a few drops of ink and honey in a separate beaker and observe the diffusion rate.
Ink drops mix with water fast and becomes even in colour within a few minutes; while honey takes time in hours to become even with water.
Different substances have different diffusion rate. They take different time to mix with the surrounding. This property varies from substance to substance and depends on the forces of attraction between own molecules and molecules of the surrounding particles. Honey has money force of attraction between their molecules than ink. As a result, honey diffuses slowly in water than ink.
This force of attraction also affects the kinetic energy of the molecule. Higher the attraction force between the same molecule, lesser is the kinetic energy of the particle.
Different substances has different diffusion rate.