Chemistry

1. Which of the following are matter?

Love, smell, hate, thought

Smell of perfume, cold

Cold, hate, smell

Ything that occupies space and has mass is called matter. Matter can exist in three physical states—solid, liquid, and gaseous. Chair and almond are forms of matter in the solid state. Cold drink is a liquid state of matter. Air is a gaseous state of matter.

2. Give reasons for the following observation: The smell of hot sizzling food reaches you several metres away, but to get the smell from cold food you have to go close.

Cold food particles are heavier and cannot travel far in the air.

Solids diffuse at a very slow rate. But, if the temperature of the solid is increased, then the rate of diffusion of the solid particles into air increases. This is due to an increase in the kinetic energy of solid particles. Hence, the smell of hot sizzling food reaches us even at a distance, but to get the smell from cold food we have to go close.

Hot food smells stronger than cold food.

The smell of hot food evaporates faster than cold food.

When solid particles are at a higher temperature, their diffusion rate into the air increases due to increased kinetic energy. This explains why the smell of hot sizzling food can be detected from a distance, while cold food requires close proximity to smell.

Explanation

When solid particles are at a higher temperature, their diffusion rate into the air increases due to increased kinetic energy. This explains why the smell of hot sizzling food can be detected from a distance, while cold food requires close proximity to smell.

3. A diver is able to cut through water in a swimming pool. Which property of matter does this observation show?

The ability of a diver to cut through water in a swimming pool shows that the particles of matter have high viscosity.

The ability of a diver to cut through water in a swimming pool shows that the particles of matter have a fixed shape.

The ability of a diver to cut through water in a swimming pool shows that the particles of matter have intermolecular spaces. The intermolecular spaces in liquids is fair enough to let the diver pass through it.

The ability of a diver to cut through water in a swimming pool shows that the particles of matter have strong intermolecular forces.

When a diver cuts through water in a swimming pool, the observation indicates that the particles of matter have intermolecular spaces, allowing the diver to pass through. This illustrates a fundamental property of matter in its liquid form.

Explanation

When a diver cuts through water in a swimming pool, the observation indicates that the particles of matter have intermolecular spaces, allowing the diver to pass through. This illustrates a fundamental property of matter in its liquid form.

4. What are the characteristics of particles of matter?

Particles of matter have fixed positions.

Particles of matter do not interact with each other.

Particles of matter have no mass.

The characteristics of particles of matter are: (i) Particles of matter have spaces between them. (ii) Particles of matter are continuously moving. (iii) Particles of mater attract each other.

Particles of matter exhibit properties such as having spaces between them, continuous movement, and attraction towards each other due to forces like gravity and electromagnetic forces.

Explanation

Particles of matter exhibit properties such as having spaces between them, continuous movement, and attraction towards each other due to forces like gravity and electromagnetic forces.

5. Arrange the following substances in order of increasing density: air, exhaust from chimney, honey, water, chalk, cotton, and iron.

Cotton < Air < Exhaust from chimney < Water < Chalk < Honey < Iron

Iron < Water < Honey < Chalk < Air < Exhaust from chimney < Cotton

The given substances in the increasing order of their densities can be represented as: Air < Exhaust from chimney < Cotton < Water < Honey < Chalk < Iron

Exhaust from chimney < Cotton < Air < Honey < Chalk < Iron < Water

The density of a substance is defined as its mass per unit volume. By comparing the densities of the given substances, the correct order can be determined based on their mass and volume relationship. It is important to consider the relative densities of each substance to accurately arrange them in increasing order.

Explanation

The density of a substance is defined as its mass per unit volume. By comparing the densities of the given substances, the correct order can be determined based on their mass and volume relationship. It is important to consider the relative densities of each substance to accurately arrange them in increasing order.