Test: States of Matter - Class 5 MCQ

Distillation is an effective method for separating a soluble solid from a liquid. It involves boiling the liquid to form vapor and then condensing it back into liquid, leaving the solid behind. This process is particularly useful for purifying liquids.

Nitrogen is the largest component of air, making up about 78% of its composition, followed by oxygen at around 21%. This balance is crucial for maintaining life on Earth, as different organisms rely on these gases for various biological processes.

Ventilation is essential for replacing stale or impure air with fresh air, improving indoor air quality. This process helps remove odors, excess moisture, and pollutants, contributing to a healthier living environment.

Filtration is the best method for separating very small insoluble solids from liquids. It works by passing the mixture through a filter paper, which allows the liquid to pass while trapping the solid particles.

Melting ice is an example of a physical change because it involves a change of state from solid to liquid without forming a new substance. The process can be reversed by cooling the water back into ice.

A chemical change is characterized by the formation of one or more new substances that have different properties from the original materials. This process is typically irreversible under normal conditions.

Solids are defined by having a fixed shape and volume because their molecules are closely packed together with strong forces of attraction. This structural arrangement prevents solids from flowing like liquids or gases, contributing to their stability in form and size.

Gas molecules are very loosely packed and have weak intermolecular forces, allowing them to move freely in all directions. This characteristic results in gases having neither a fixed shape nor a fixed volume, allowing them to expand and fill any available space.

Liquids do not have a fixed shape; instead, they adapt to the shape of their container while maintaining a fixed volume. This is due to the weaker forces of attraction between their molecules, which allows them to move freely compared to solids.

Solubility refers to the ability of a substance (the solute) to dissolve in another substance (the solvent) to form a solution. Water is known as the universal solvent because a wide variety of substances can dissolve in it.

At night, the land cools more quickly than the sea, causing the air above the land to become cooler and denser. This cooler air moves towards the sea, creating a land breeze as it replaces the warmer air above the sea.

In distillation, applying heat to a solution causes the solvent to evaporate while leaving the solute behind. The vapor is then cooled and condensed back into liquid form, effectively separating the components of the solution. This process is commonly used in the purification of liquids.

Sedimentation involves allowing heavy particles within a mixture to settle at the bottom of a container due to gravity. This process is often the first step in separating solids from liquids in various applications.

Gases have weak forces of attraction between their molecules, which allows them to move freely and expand to fill any available space in a container. This property distinguishes gases from solids and liquids.

Warm air is lighter than cold air due to its lower density. As the air heats up, it expands, becoming less dense and causing it to rise, which in turn allows cooler, denser air to move in and take its place.

Oxygen is critical for the survival of aquatic animals, as they rely on it for respiration. It dissolves in water and is absorbed by fish and other aquatic organisms through their gills.

Oil and water are classic examples of immiscible liquids. When mixed, they do not combine and instead separate into distinct layers due to differences in their densities and molecular structures.

During the day, the land heats up faster than the sea, causing the warm air above the land to rise. This creates a low-pressure area that draws in cooler air from the sea, resulting in a sea breeze.

The primary distinction is that miscible liquids can mix and dissolve in one another completely, while immiscible liquids do not mix and form separate layers. For example, water and alcohol are miscible, while oil and water are immiscible.

Burning wood is a chemical change because it results in the formation of new substances, such as ash and smoke, that cannot be reversed back into wood. This process involves a chemical reaction with oxygen.