Particulate Nature of Matter Class 8 Long Question Answer

Particulate Nature of Matter Class 8 Long Question Answer

Particulate Nature of Matter Class 8 Long Question Answer

Question 1.

Explain the differences in the arrangement and movement of particles in solids, liquids, and gases.

Answer:

1. In solids, particles are closely packed together in a fixed arrangement. This arrangement gives solids a definite shape and volume.
2. In liquids, particles can move past one another, allowing liquids to take the shape of their container while maintaining a definite volume.
3. In gases, particles are far apart with negligible inter particle attractions. This results in gases having neither a fixed shape nor a fixed volume.

Question 2.

Describe the process of melting and how it relates to the changes in inter particle forces and spacing.

Answer:

1. Melting is the process in which a solid transforms into a liquid upon the addition of heat.
2. As the temperature increases, the thermal energy of the particles in the solid also increases, causing them to vibrate more vigorously.
3. At the melting point, the particles begin to move apart, increasing the interparticle spacing and reducing the strength of the attractive forces.

Question 3.

Why do gases mix easily while solids do not? Discuss the role of interparticle spacing and movement in this phenomenon.

Answer:

1. Gases mix easily due to the high kinetic energy of their particles and the large interparticle spacing that allows them to move freely and collide with one another.
2. The negligible interparticle attractions in gases mean that when different gas particles come into contact, they can easily intermingle and spread throughout the available space.
3. Therefore, the differences in interparticle spacing and movement are key factors in the mixing behaviour of gases compared to solids.

Examples from daily life:

Question 1.

The Fragrance of Perfume

Answer:

When you spray perfume in one corner of a room, the scent spreads throughout the space. This happens because the particles of the fragrance are in a gaseous state and move rapidly in all directions. The particles move from an area of higher concentration (near the spray) to an area of lower concentration (the rest of the room).

Question 2.

The Behaviour of Ice in Water

Answer:

When ice is placed in water, it floats due to its unique structure. Ice is less dense than liquid water because, in its solid state. This is an interesting exception to the general rule that solids are denser than liquids. This illustrates the differences in interparticle spacing between solids and liquids but also highlights the concept of melting and the changes in state of matter.