Worksheet Solutions: Air, Water, Soil | General Knowledge for Young Learners - Class 1 PDF Download

Section A: Fill in the blanks

Q1: Air is a mixture of _______.

Ans: gases
Explanation: Air is not a pure substance but rather a combination of different gases, along with some other particles such as dust and water vapor. It is composed of a mixture of various gases that are present in the Earth's atmosphere.

Q2: The composition of air includes _______% nitrogen and _______% oxygen.

Ans: 78%, 21%
Explanation: Nitrogen is the most abundant gas in the Earth's atmosphere, accounting for about 78% of the total composition. Oxygen is the second most abundant gas, making up approximately 21% of the air we breathe.

Q3: Living things like plants produce oxygen by converting _______.

Ans: carbon dioxide
Explanation: Through the process of photosynthesis, plants utilize carbon dioxide (CO2) from the air, along with water and sunlight, to produce oxygen (O2) and glucose. This process is crucial for maintaining the oxygen levels in the atmosphere and is a primary source of the oxygen we breathe.

Q4: Animals use oxygen to produce _______ from the food they eat.

Ans: energy
Explanation: Animals undergo a process called respiration, where they take in oxygen from the air and use it to break down the food they consume. This process releases energy in the form of ATP (adenosine triphosphate), which is used by the body for various functions, including growth, movement, and reproduction.

Q5: Plants require _______ to trap energy from the sun.

Ans: sunlight
Explanation: Through the process of photosynthesis, plants capture energy from sunlight and convert it into chemical energy in the form of glucose. Sunlight is the primary source of energy for plants, and they utilize it to fuel their metabolic processes and growth.

Q6: The movements of air are commonly known as _______.

Ans: wind
Explanation: Wind refers to the natural movement of air in the Earth's atmosphere. It is caused by the uneven heating of the Earth's surface by the sun, which creates differences in air pressure. As air moves from high-pressure areas to low-pressure areas, it generates wind currents.

Q7: Polluting the air with hazardous chemicals can _______ the existence of life.

Ans: threaten
Explanation: Air pollution caused by the release of hazardous chemicals and pollutants can have severe consequences on both human health and the environment. It can lead to respiratory problems, cardiovascular diseases, and damage ecosystems, thus posing a threat to the existence of life.

Q8: Water is considered the _______ of life.

Ans: medium
Explanation: Water is essential for all forms of life on Earth. It plays a vital role in various biological processes and is a fundamental requirement for survival. From providing a medium for chemical reactions within cells to regulating body temperature, water is often referred to as the "source of life."

Q9: The majority of water on Earth is found in the _______ and is too salty to drink.

Ans: oceans
Explanation: Approximately 97% of Earth's water is found in the oceans, which are characterized by their high salt content. This water is not suitable for drinking or most agricultural purposes without undergoing desalination processes to remove the excess salt.

Q10: Soil contains minerals and _______ that are essential for sustaining life.

Ans: water
Explanation: Soil is a complex mixture of minerals, organic matter, water, air, and living organisms. It serves as a medium for plant growth and provides essential nutrients such as nitrogen, phosphorus, and potassium. These minerals and nutrients are necessary for sustaining life as they support the growth and development of plants, which form the base of the food chain.

Section B: True or False

Q1: Air is essential for living things to survive.

Ans: True
Explanation: Air is crucial for the survival of living things, including humans, animals, and plants. It contains oxygen, which is necessary for the process of respiration. Oxygen is used by living organisms to convert food into energy. Additionally, air also contains other gases like nitrogen, carbon dioxide, and trace gases that play important roles in various biological and ecological processes.

Q2: Water is a renewable resource.

Ans: True
Explanation: Water is a renewable resource because it is part of the Earth's hydrological cycle. The hydrological cycle involves the continuous movement of water through various stages, including evaporation, condensation, precipitation, and runoff. As a result, water is replenished and recycled over time. However, it is important to note that some regions may face water scarcity due to factors such as droughts, pollution, or overuse.

Q3: Soil is made up of living organisms, rocks, and minerals.

Ans: True
Explanation: Soil is a complex mixture of organic matter (such as decomposed plants and animals), rocks, minerals, water, and air. It also contains countless living organisms, including bacteria, fungi, insects, worms, and plant roots. These organisms contribute to the decomposition of organic matter, nutrient cycling, and soil fertility. The composition of soil varies from one location to another, depending on factors such as climate, parent material, vegetation, and time.

Q4: Air pollution can have harmful effects on human health.

Ans: True
Explanation: Air pollution can indeed have detrimental effects on human health. When the air is contaminated with pollutants such as fine particulate matter (PM2.5), nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), ozone (O3), and volatile organic compounds (VOCs), it can lead to respiratory problems, cardiovascular issues, allergies, and other health complications. Prolonged exposure to polluted air can increase the risk of developing respiratory diseases, such as asthma, bronchitis, and even lung cancer.

Q5: Soil erosion is beneficial for agriculture.

Ans: False
Explanation: Soil erosion is generally not beneficial for agriculture. Soil erosion refers to the process of the top layer of soil being washed away or blown off due to factors like wind, water, or human activities. It can lead to the loss of fertile topsoil, which is essential for plant growth and crop production. Soil erosion can negatively impact agricultural productivity by reducing soil fertility, water-holding capacity, and nutrient availability. It is crucial to employ erosion control measures, such as terracing, contour plowing, and planting cover crops, to prevent excessive soil erosion and maintain soil health for sustainable agriculture.