Keywords To Remember
- Atmosphere: The thick layer of gases surrounding the Earth, composed mainly of nitrogen, oxygen, carbon dioxide, and other trace gases.
- Troposphere: The lowest layer of the Earth’s atmosphere, where weather events like clouds, rain, and winds occur.
- Stratosphere: The layer of the atmosphere above the troposphere, characterized by a stable temperature and the presence of the ozone layer.
- Mesosphere: The third layer of the Earth’s atmosphere, where temperature decreases with altitude and meteors burn up.
- Thermosphere: The layer of the atmosphere above the mesosphere, where temperatures increase with height and ionized particles exist, important for radio communications.
- Tropopause: The boundary layer between the troposphere and the stratosphere.
- Ozone Layer: A layer in the stratosphere that contains a high concentration of ozone molecules (O₃), which absorb harmful ultraviolet radiation from the Sun.
- Ionosphere: A layer in the thermosphere composed of ionized particles that are essential for radio communication.
- Nitrogen: A major constituent of the Earth’s atmosphere, comprising 78% of the air, which is essential for plant growth but not directly useful for humans and animals.
- Oxygen: A life-sustaining gas that makes up 21% of the atmosphere, used by living organisms for respiration.
- Carbon Dioxide (CO₂): A gas present in small amounts in the atmosphere (0.03%), crucial for photosynthesis in plants and a contributor to global warming.
- Argon: An inert gas that makes up about 0.90% of the Earth’s atmosphere.
- Methane (CH₄): A greenhouse gas found in trace amounts in the atmosphere, contributing to global warming.
- Global Warming: The gradual increase in Earth’s atmospheric temperature due to higher concentrations of greenhouse gases like carbon dioxide.
- Pollution: The introduction of harmful substances (gases, liquids, or solids) into the environment, causing harm to living organisms and the Earth.
- Air Pollution: The presence of harmful substances, such as carbon monoxide, sulfur dioxide, and particulate matter, in the air, often caused by human activities like vehicle emissions and industrial processes.
- Smog: A type of air pollution formed by the combination of smoke and fog, often leading to respiratory problems and irritation in the eyes.
- Condensation: The process by which water vapour in the air turns into liquid water droplets, forming clouds.
- Precipitation: Any form of water, such as rain, snow, sleet, or hail, that falls from the atmosphere to the Earth.
- Evaporation: The process by which water is converted into water vapour and rises into the atmosphere.
- Transpiration: The release of water vapour from plants into the atmosphere, contributing to the water cycle.
- Runoff: The flow of water, usually from precipitation, over the Earth’s surface, often carrying pollutants.
- Rain Gauge: An instrument used to measure the amount of rainfall over a specific period of time.
- Weather: The short-term atmospheric conditions in a specific place at a particular time, including temperature, humidity, wind, and precipitation.
- Climate: The long-term average of weather conditions in a particular area, including temperature and precipitation patterns over a large period of time.
- Monsoon: A seasonal wind pattern that brings heavy rains, primarily in tropical and subtropical regions.
- Photosynthesis: The process by which plants use sunlight, carbon dioxide, and water to produce their own food in the form of glucose and release oxygen.
- Barometer: An instrument used to measure atmospheric pressure, often used in weather forecasting.
- Humidity: The amount of water vapour present in the air, which affects weather patterns and comfort levels.
- Wind: The movement of air from areas of high pressure to low pressure, responsible for weather changes and ocean currents.
Something To Know
A. Tick (✔) the correct option.
- In normal lapse rate, temperature decreases at the rate of 1°C with every-
(a) 165 m ascend
(b) 175 m ascend
(c) 185 m ascend
(d) 195 m ascend
Answer – (b) 175 m ascend
- Which layer is safe for flying aircrafts?
(a) troposphere
(b) stratosphere
(c) mesosphere
(d) thermosphere
Answer – (b) stratosphere
- The role of ion-particles in the ionosphere is to-
(a) absorb ultra violet rays
(b) enable wireless communication
(c) burn meteors
(d) enable rainfall
Answer – (b) enable wireless communication
- Which one of the following is the main cause of global warming?
(a) air pollution
(b) water pollution
(c) soil pollution
(d) land degradation
Answer – (a) air pollution
- Smog causes-
(a) breathing problems
(b) purification of air
(d) reduction in temperature
(c) heavy rainfall
Answer – (a) breathing problems
B. Fill in the blanks.
- Atmosphere is mainly composed of three major gases-nitrogen, ________
and ________ amounts in the air.
Answer – oxygen, small
- Gases like argon, helium, methane, etc, are present in ________ amounts in the air.
Answer – trace
- All weather phenomena occur in the ________
Answer – troposphere
- Atmospheric conditions over a long period of time and on a larger area is called ________ .
Answer – climate
- The normal air pressure at sea level is ________ .
Answer – 1013.25 hPa
C. Match the following:
- Mono-oxide gas a. Weight or pressure exerted by the air.
- Weather b. Most harmful gas present in the atmosphere.
- Barometer c. The falling of water drops on the earth’s surface.
- Atmospheric Pressure d. An instrument to measure atmospheric pressure.
- Rainfall e. Atmospheric conditions for a specific place covering a short period of time.
Answer –
Mono-oxide gas – b. Most harmful gas present in the atmosphere.
Weather – e. Atmospheric conditions for a specific place covering a short period of time.
Barometer – d. An instrument to measure atmospheric pressure.
Atmospheric Pressure – a. Weight or pressure exerted by the air.
Rainfall – c. The falling of water drops on the earth’s surface.
Answer –
1 → b
2 → e
3 → d
4 → a
5 → c
D. Answer the following questions in brief.
- Name the layer of the atmosphere.
Answer – The layers of the atmosphere are:
Troposphere
Stratosphere
Mesosphere
Thermosphere
Exosphere
- How do plants absorb nitrogen?
Answer – Plants absorb nitrogen primarily in the form of nitrates and ammonium ions from the soil, which are produced through the nitrogen cycle, especially through processes like nitrogen fixation by bacteria.
- What is the importance of water vapours in the atmosphere?
Answer – Water vapours are important because they contribute to the formation of clouds, precipitation (rain, snow), and affect weather patterns. They also help in regulating the Earth’s temperature by absorbing and releasing heat.
- Name the different variables of atmosphere.
Answer – The main variables of the atmosphere include temperature, humidity, air pressure, wind, and precipitation.
- What type of climate does India have?
Answer – India has a tropical monsoon climate, characterized by hot summers, a rainy monsoon season, and mild winters.
E. Answer the following questions
- What is the importance of carbon dioxide and oxygen for living beings?
Answer – Carbon dioxide (CO2) is crucial for plants, as they use it for photosynthesis, which helps in producing oxygen and food (glucose).
Oxygen (O2) is essential for the respiration of most living organisms, providing the necessary energy for survival.
- Name three major sources of pollutants in the air. Also state the ill-effects of these air pollutants.
Answer – Sources of air pollutants:
Industrial emissions (factories, power plants)
Vehicle exhaust gases
Agricultural activities (pesticides, fertilizers)
Ill-effects of air pollutants:
Respiratory diseases (asthma, bronchitis)
Heart problems
Environmental damage (acid rain, global warming)
- What is the importance of ozone gas? Why is global warming a threat to life on the earth?
Answer – Importance of ozone gas: Ozone forms a protective layer in the stratosphere, absorbing harmful ultraviolet (UV) radiation from the sun, which can cause skin cancer, eye damage, and other health issues.
Global warming threat: Global warming leads to rising temperatures, melting ice caps, and changing weather patterns, threatening ecosystems, agriculture, water supply, and human life.
- How is rainfall caused? Explain it with the help of a diagram.
Answer – Rainfall occurs due to the condensation of water vapor in the atmosphere. When warm, moist air rises, it cools and the water vapor condenses into tiny droplets, forming clouds. When the droplets combine and become heavy enough, they fall as rain.
- Write the difference between weather and climate.
Answer – Weather refers to the atmospheric conditions of a specific place at a particular time (short term).
Climate refers to the average weather conditions over a long period of time (typically 30 years) for a region.
Value Based Question
‘Global warning is threatening the life support system of the earth.’
- How can we relate our life with it? Give examples in support of your answer.
Answer – Global warming affects our daily lives in many ways. For example, the rising temperatures lead to heatwaves, crop failures, and water shortages, all of which directly impact human health, food security, and water availability. Additionally, it can result in the loss of biodiversity and increased natural disasters like floods and droughts.
- Explain any two measures to combat this problem.
Answer – Reduction of greenhouse gas emissions: Transitioning to renewable energy sources like solar, wind, and hydroelectric power can significantly reduce the release of harmful gases such as CO2.
Afforestation and reforestation: Planting trees helps absorb carbon dioxide and regulate the climate, reducing the overall effects of global warming.
Something To Do
- Collect the weather report of the last week from the newspapers and write it in the following tabula form.
Day
Monday
Tuesday
Wednesday Thursday
Friday
Saturday
Sunday
Date
Weather Report
Answer – Students will do these PPTs at their own.
- Make a PowerPoint presentation on the following topics and present it in the class.
(a) Global warming
(b) Air pollution
Answer – Students will to these PPTs at their own.
Additional Questions and Answers – 01
Fill in the Blanks (with Answers)
- The troposphere is the lowest layer of the atmosphere.
Answer – troposphere - The layer that contains the ozone layer is called the stratosphere.
Answer – stratosphere - The main component of the atmosphere is nitrogen, making up about 78%.
Answer – nitrogen - The barometer is used to measure atmospheric pressure.
Answer – barometer - Ozone gas protects us from harmful UV rays.
Answer – Ozone - The process by which water vapor changes into water droplets is called condensation.
Answer – condensation - The percentage of oxygen in the atmosphere is approximately 21%.
Answer – 21% - Air exerts pressure in all directions.
Answer – pressure - Weather is the condition of the atmosphere at a particular place and time.
Answer – Weather - The mesosphere is the coldest layer of the atmosphere.
Answer – mesosphere
Multiple Choice Questions (MCQs)
- Which gas is most abundant in the Earth’s atmosphere?
(a) Oxygen
(b) Carbon dioxide
(c) Nitrogen
(d) Hydrogen
Answer – (c) Nitrogen - Which layer contains the ozone layer?
(a) Troposphere
(b) Stratosphere
(c) Mesosphere
(d) Thermosphere
Answer – (b) Stratosphere - Which layer helps in radio communication?
(a) Troposphere
(b) Exosphere
(c) Ionosphere
(d) Mesosphere
Answer – (c) Ionosphere - What is the normal air pressure at sea level?
(a) 101.3 Pa
(b) 1013 mb
(c) 1000 Pa
(d) 1031 mb
Answer – (b) 1013 mb - Which of the following causes acid rain?
(a) Oxygen
(b) Nitrogen
(c) Sulphur dioxide
(d) Hydrogen
Answer – (c) Sulphur dioxide
True or False
- Carbon dioxide is harmful for photosynthesis.
False - Ozone layer absorbs ultraviolet radiation.
True - The thermosphere is the coldest part of the atmosphere.
False - Air pressure increases as we go higher in the atmosphere.
False - Water vapor plays a role in weather formation.
True - Plants cannot use atmospheric nitrogen directly.
True - Troposphere is the layer where life exists.
True - Weather remains the same throughout the year.
False
Competency-Based Questions
- Question: Ravi observed that it was very hot and humid one day, followed by heavy rain and cool weather the next day. What atmospheric process explains this change?
Answer: The weather change is due to water vapor in the atmosphere condensing to form clouds, leading to rainfall, followed by a drop in temperature. - Question: Why do mountaineers carry oxygen cylinders while climbing high mountains?
Answer: Because at high altitudes, the atmospheric pressure and oxygen levels are low, making it difficult to breathe. - Question: Why is the stratosphere suitable for flying aircrafts?
Answer: Because it has stable air with minimal weather disturbances, ensuring smooth flying conditions.
Higher Order Thinking Skills (HOTS) Questions
- Question: What would happen if the ozone layer gets completely destroyed?
Answer: Harmful ultraviolet rays from the sun would reach the Earth directly, increasing the risk of skin cancer, damaging crops, marine life, and disturbing the ecological balance. - Question: How can human activities contribute to changes in atmospheric composition?
Answer: Human activities like burning fossil fuels, deforestation, and industrial emissions release pollutants and greenhouse gases, altering the natural composition and affecting weather and climate.
Short Answer Questions
- What is the atmosphere?
Answer: The atmosphere is a blanket of gases that surrounds the Earth and is essential for supporting life. - What is meant by weather?
Answer: Weather is the day-to-day condition of the atmosphere at a particular place. - Why is oxygen important for living beings?
Answer: Oxygen is necessary for respiration, the process by which living beings release energy. - What is air pressure?
Answer: Air pressure is the force exerted by the weight of air on the Earth’s surface. - Name any two human activities that cause air pollution.
Answer: Burning of fossil fuels and industrial emissions.
Long Answer Questions
- Describe the different layers of the atmosphere with their characteristics.
Answer:- Troposphere: Lowest layer where weather occurs, temperature decreases with altitude.
- Stratosphere: Contains ozone layer, suitable for flying airplanes.
- Mesosphere: Coldest layer, burns up meteors.
- Thermosphere: High temperatures, contains ionosphere, helps in radio communication.
- Exosphere: Outermost layer, merges with outer space.
- Explain the greenhouse effect and its consequences.
Answer:
The greenhouse effect occurs when greenhouse gases like CO₂ and methane trap heat in the Earth’s atmosphere, keeping it warm. While this is essential for life, excessive greenhouse gases cause global warming, leading to melting ice caps, rising sea levels, and extreme weather events. - How do human activities affect the atmosphere? Explain with examples.
Answer:
Human activities such as burning coal and petrol, deforestation, industrialization, and use of CFCs release harmful gases into the atmosphere, leading to pollution, global warming, ozone depletion, and acid rain. For example, excessive vehicle use increases carbon monoxide levels, harming health.
Additional Questions and Answers – 01
Fill in the Blanks Questions and Answers
- Question: The Earth is surrounded by a thick layer of air called the ______.
Answer: The Earth is surrounded by a thick layer of air called the atmosphere. - Question: The atmosphere started forming about ______ million years ago.
Answer: The atmosphere started forming about 4600 million years ago. - Question: The atmosphere is divided into four layers: Troposphere, Stratosphere, Mesosphere, and ______.
Answer: The atmosphere is divided into four layers: Troposphere, Stratosphere, Mesosphere, and Thermosphere. - Question: The ______ is the densest layer of the atmosphere where weather changes occur.
Answer: The Troposphere is the densest layer of the atmosphere where weather changes occur. - Question: In the Troposphere, the temperature decreases by 1°C for every ______ meters ascend.
Answer: In the Troposphere, the temperature decreases by 1°C for every 165 meters ascend. - Question: The layer above the Troposphere with calm and clear air is called the ______.
Answer: The layer above the Troposphere with calm and clear air is called the Stratosphere. - Question: The ______ layer in the Stratosphere absorbs harmful ultraviolet rays from the Sun.
Answer: The ozone layer in the Stratosphere absorbs harmful ultraviolet rays from the Sun. - Question: The boundary between the Troposphere and Stratosphere is called the ______.
Answer: The boundary between the Troposphere and Stratosphere is called the tropopause. - Question: Meteors burn up in the ______ layer of the atmosphere.
Answer: Meteors burn up in the Mesosphere layer of the atmosphere. - Question: The ______ layer contains ion-particles that help in wireless communication.
Answer: The Thermosphere layer contains ion-particles that help in wireless communication. - Question: The air we inhale is a mixture of gases, with ______ occupying 78% of the total volume.
Answer: The air we inhale is a mixture of gases, with nitrogen occupying 78% of the total volume. - Question: Oxygen makes up about ______% of the air and is essential for life.
Answer: Oxygen makes up about 21% of the air and is essential for life. - Question: Carbon dioxide constitutes ______% of the air and is used by plants in photosynthesis.
Answer: Carbon dioxide constitutes 03% of the air and is used by plants in photosynthesis. - Question: Excessive carbon dioxide in the air can lead to ______, increasing the Earth’s temperature.
Answer: Excessive carbon dioxide in the air can lead to global warming, increasing the Earth’s temperature. - Question: Gaseous pollutants like carbon monoxide and sulphur dioxide are released by ______.
Answer: Gaseous pollutants like carbon monoxide and sulphur dioxide are released by automobiles. - Question: The combination of smoke particles and fog forms ______, causing health issues.
Answer: The combination of smoke particles and fog forms smog, causing health issues. - Question: The normal air pressure at sea level is ______ millibar.
Answer: The normal air pressure at sea level is 1,013 - Question: Wind flows from a ______ pressure area to a low pressure area.
Answer: Wind flows from a high pressure area to a low pressure area. - Question: The ______ is a seasonal wind phenomenon that brings rainfall to India.
Answer: The monsoon is a seasonal wind phenomenon that brings rainfall to India. - Question: Rainfall is measured using an instrument called a ______.
Answer: Rainfall is measured using an instrument called a rain gauge.
Multiple Choice Questions and Answers
- Question: How long ago did the Earth’s atmosphere start forming?
a) 3600 million years
b) 4600 million years
c) 5600 million years
d) 2600 million years
Answer: b) 4600 million years - Question: How many layers is the atmosphere divided into?
a) Three
b) Four
c) Five
d) Six
Answer: b) Four - Question: Which layer of the atmosphere is the densest?
a) Stratosphere
b) Mesosphere
c) Troposphere
d) Thermosphere
Answer: c) Troposphere - Question: What is the rate of temperature decrease in the Troposphere per 165 meters ascend?
a) 0.5°C
b) 1°C
c) 2°C
d) 3°C
Answer: b) 1°C - Question: Why do aircrafts often fly in the lower Stratosphere?
a) Presence of water vapours
b) Better visibility
c) High temperature
d) Presence of dust particles
Answer: b) Better visibility - Question: What does the ozone layer in the Stratosphere do?
a) Causes global warming
b) Absorbs ultraviolet rays
c) Supports rainfall
d) Reflects radio waves
Answer: b) Absorbs ultraviolet rays - Question: In which layer do meteors burn up?
a) Troposphere
b) Stratosphere
c) Mesosphere
d) Thermosphere
Answer: c) Mesosphere - Question: Which layer contains ion-particles that aid wireless communication?
a) Troposphere
b) Stratosphere
c) Mesosphere
d) Thermosphere
Answer: d) Thermosphere - Question: What is the most abundant gas in the atmosphere?
a) Oxygen
b) Nitrogen
c) Carbon dioxide
d) Argon
Answer: b) Nitrogen - Question: What percentage of the air is oxygen?
a) 78%
b) 21%
c) 0.03%
d) 0.9%
Answer: b) 21% - Question: Which gas is essential for photosynthesis in plants?
a) Nitrogen
b) Oxygen
c) Carbon dioxide
d) Helium
Answer: c) Carbon dioxide - Question: What is the percentage of carbon dioxide in the air?
a) 21%
b) 78%
c) 0.03%
d) 0.9%
Answer: c) 0.03% - Question: What can excessive carbon dioxide in the air cause?
a) Global cooling
b) Global warming
c) Rainfall
d) Wind movement
Answer: b) Global warming - Question: Which of the following is a pollutant released by automobiles?
a) Nitrogen
b) Carbon monoxide
c) Oxygen
d) Water vapor
Answer: b) Carbon monoxide - Question: What forms when smoke particles combine with fog?
a) Rain
b) Smog
c) Clouds
d) Wind
Answer: b) Smog - Question: What is the normal air pressure at sea level?
a) 1,000 millibar
b) 1,013 millibar
c) 1,050 millibar
d) 990 millibar
Answer: b) 1,013 millibar - Question: Wind flows from:
a) Low to high pressure area
b) High to low pressure area
c) Equal pressure areas
d) Cold to hot areas
Answer: b) High to low pressure area - Question: What seasonal wind phenomenon brings rainfall to India?
a) Tornado
b) Cyclone
c) Monsoon
d) Breeze
Answer: c) Monsoon - Question: What instrument is used to measure rainfall?
a) Barometer
b) Rain gauge
c) Thermometer
d) Wind vane
Answer: b) Rain gauge - Question: What does weather refer to?
a) Long-term atmospheric conditions
b) Short-term atmospheric state
c) Annual rainfall
d) Seasonal winds
Answer: b) Short-term atmospheric state
True/False Questions and Answers
- Question: The Earth’s atmosphere started forming 4600 million years ago.
Answer: True - Question: The atmosphere has five layers.
Answer: False (It has four layers: Troposphere, Stratosphere, Mesosphere, and Thermosphere.) - Question: The Troposphere is the densest layer of the atmosphere.
Answer: True - Question: Temperature increases with height in the Troposphere.
Answer: False (Temperature decreases with height in the Troposphere.) - Question: The Stratosphere contains water vapors and dust particles.
Answer: False (It lacks water vapors and dust, preventing cloud formation.) - Question: The ozone layer absorbs harmful ultraviolet rays.
Answer: True - Question: Meteors burn up in the Thermosphere.
Answer: False (They burn up in the Mesosphere.) - Question: The Thermosphere aids in wireless communication due to ion-particles.
Answer: True - Question: Nitrogen is the most abundant gas in the air at 78%.
Answer: True - Question: Oxygen makes up 0.03% of the air.
Answer: False (Oxygen makes up 21% of the air.) - Question: Carbon dioxide is used by plants in photosynthesis.
Answer: True - Question: Excessive carbon dioxide causes global cooling.
Answer: False (It causes global warming.) - Question: Automobiles release pollutants like carbon monoxide and sulphur dioxide.
Answer: True - Question: Smog is a combination of smoke and rain.
Answer: False (Smog is a combination of smoke and fog.) - Question: The normal air pressure at sea level is 1,013 millibar.
Answer: True - Question: Wind flows from a low pressure area to a high pressure area.
Answer: False (Wind flows from a high pressure area to a low pressure area.) - Question: Monsoon winds bring rainfall to India.
Answer: True - Question: Rainfall is measured using a barometer.
Answer: False (Rainfall is measured using a rain gauge.) - Question: Weather refers to atmospheric conditions over a long period of time.
Answer: False (Weather refers to short-term conditions; climate refers to long-term conditions.) - Question: Weather reports include information on temperature, humidity, and wind velocity.
Answer: True
Competency-Based Questions and Answers
- Question: A student learns that the Troposphere is where weather changes occur. Why might this layer be critical for human life?
Answer: The Troposphere is critical for human life because it contains water vapours and dust particles that enable weather phenomena like rainfall, which provides water for drinking, agriculture, and ecosystems. Its dense air supplies oxygen for breathing, and weather changes regulate temperature, ensuring a habitable environment for humans, plants, and animals to thrive. - Question: During a class discussion, you hear that aircraft fly in the Stratosphere for better visibility. How does this benefit air travel?
Answer: Flying in the Stratosphere benefits air travel by providing clear visibility due to the absence of water vapors and dust particles, which prevents cloud formation. This ensures smoother flights, reduces turbulence, and enhances safety. Additionally, it allows pilots to navigate more efficiently, saving fuel and time while improving the overall flying experience for passengers. - Question: A teacher mentions that the ozone layer absorbs ultraviolet rays. Why is this important for life on Earth?
Answer: The ozone layer’s absorption of ultraviolet rays is crucial as it protects life on Earth from harmful radiation that can cause skin cancer, allergies, and damage ecosystems. Without this shield, life would be impossible, as UV rays would harm plants, animals, and humans, disrupting food chains and making the Earth’s surface uninhabitable, highlighting the ozone’s role in sustaining life. - Question: You read that the Thermosphere aids wireless communication. How does this impact modern technology?
Answer: The Thermosphere’s ion-particles in the ionosphere reflect radio waves, enabling wireless communication across long distances. This impacts modern technology by supporting global communication networks, including radio, television, and satellite signals, ensuring connectivity for navigation, broadcasting, and internet services, which are essential for daily life, emergencies, and global coordination in today’s interconnected world. - Question: A classmate notes that plants replenish oxygen through photosynthesis. Why is this process vital for maintaining air quality?
Answer: Photosynthesis by plants is vital for maintaining air quality as it replenishes oxygen, which all living organisms need to survive. Plants absorb carbon dioxide and release oxygen, balancing atmospheric gases, reducing CO2 levels that cause global warming, and ensuring a steady oxygen supply, making green plants essential for a healthy, breathable atmosphere and sustainable ecosystems. - Question: During a project, you learn that carbon dioxide causes global warming. How might human activities contribute to this issue?
Answer: Human activities like burning fossil fuels in automobiles and industries release excess carbon dioxide, which traps heat and causes global warming. Deforestation reduces the number of plants that absorb CO2 through photosynthesis, while agricultural practices like burning husk add pollutants, increasing atmospheric CO2 levels, raising temperatures, and threatening life support systems by altering climate patterns. - Question: You observe that wind flows from high to low pressure areas. How does this principle explain the monsoon in India?
Answer: The monsoon in India occurs because land heats up faster than water, creating a low pressure area over the land and a high pressure area over the ocean. Winds flow from the high pressure ocean to the low pressure land, bringing moisture that causes rainfall, supporting agriculture and water supply, illustrating how pressure differences drive seasonal weather patterns. - Question: A news report highlights air pollution from automobiles. What steps can be taken to reduce pollutants in the atmosphere?
Answer: To reduce air pollutants, we can use public transportation or electric vehicles to lower emissions from automobiles, promote renewable energy sources, and plant more trees to absorb CO2. Raising awareness about pollution, enforcing stricter emission laws, and reducing deforestation can also help minimize pollutants like carbon monoxide and sulphur dioxide, improving air quality and public health. - Question: You learn that rainfall is measured using a rain gauge. Why is measuring rainfall important for a country like India?
Answer: Measuring rainfall is important for India because it relies on monsoon rains for agriculture, which supports the economy and food supply. A rain gauge helps predict water availability, plan irrigation, and manage droughts or floods, ensuring farmers can grow crops effectively, while also aiding in disaster preparedness and water resource management for millions of people. - Question: A teacher explains that weather reports provide daily forecasts. How do these reports benefit people in their daily lives?
Answer: Weather reports benefit people by providing forecasts on temperature, rainfall, and wind, helping them plan daily activities like travel, farming, or outdoor events. They aid in preparing for extreme weather, such as storms or heatwaves, ensuring safety and comfort, while also informing decisions on clothing, transportation, and emergency measures, enhancing overall preparedness and convenience in daily life.
High Order Thinking Skills (HOTS) Questions and Answers
- Question: Why do you think the Troposphere’s temperature decreases with altitude, and how does this affect weather patterns?
Answer: The Troposphere’s temperature decreases with altitude because air density reduces, and less heat is trapped higher up. This normal lapse rate (1°C per 165 m) creates conditions for weather patterns, as warm air rises, cools, and condenses into clouds, leading to rainfall or storms, driving dynamic weather changes essential for distributing water and regulating climate on Earth. - Question: How might the absence of the ozone layer in the Stratosphere impact life on Earth, considering its role in absorbing UV rays?
Answer: Without the ozone layer, harmful UV rays would reach the Earth’s surface, causing widespread skin cancer, allergies, and eye damage in humans, while disrupting plant photosynthesis and aquatic ecosystems. This would lead to food chain collapse, biodiversity loss, and an uninhabitable environment, as UV radiation would destroy essential life forms, making the Earth a lifeless planet like others in space. - Question: Why might the Thermosphere’s ion-particles be critical for global communication, and what challenges could arise if this layer were disrupted?
Answer: The Thermosphere’s ion-particles reflect radio waves, enabling global wireless communication for radio, TV, and satellites. If disrupted, possibly by solar flares or atmospheric changes, communication networks could fail, affecting navigation, broadcasting, and internet services, leading to global connectivity issues, economic losses, and challenges in emergency response, highlighting the layer’s critical role in modern technology-dependent societies. - Question: How does the balance of oxygen and carbon dioxide in the atmosphere demonstrate the interdependence of plants and animals?
Answer: Plants produce oxygen through photosynthesis, which animals and humans inhale to survive, while animals exhale carbon dioxide, which plants use for photosynthesis. This cycle maintains atmospheric balance, ensuring oxygen for respiration and CO2 for plant growth, demonstrating interdependence where plants and animals sustain each other, supporting life and regulating climate by controlling CO2 levels that affect global warming. - Question: Why might excessive carbon dioxide in the atmosphere pose a threat to the Earth’s life support system, and what can be done to mitigate this?
Answer: Excessive carbon dioxide traps heat, causing global warming, which raises temperatures, melts ice caps, raises sea levels, and disrupts ecosystems, threatening life support systems. Mitigation includes reducing fossil fuel use, promoting renewable energy, afforestation to absorb CO2, and global policies to limit emissions, ensuring a balanced atmosphere to sustain life and prevent climate-related disasters like floods and droughts. - Question: How does the monsoon phenomenon in India illustrate the relationship between atmospheric pressure and wind movement?
Answer: The monsoon illustrates how unequal heating creates pressure differences, with land heating faster than the ocean, forming a low pressure area over land and high pressure over the sea. Winds flow from high to low pressure, carrying moisture from the ocean to land, causing rainfall. This shows how pressure gradients drive wind movement, shaping seasonal weather patterns critical for India’s agriculture. - Question: Why might air pollution from automobiles and forest fires be a growing concern, and how does it affect human health and the environment?
Answer: Air pollution from automobiles and forest fires releases pollutants like carbon monoxide and sulphur dioxide, forming smog, which causes respiratory diseases, eye irritation, and skin issues in humans. It also harms the environment by increasing CO2, contributing to global warming, and damaging ecosystems. Growing vehicle use and deforestation exacerbate this, necessitating cleaner technologies and conservation to protect health and the planet. - Question: How does the mechanism of rainfall demonstrate the interaction between temperature, pressure, and water vapor in the atmosphere?
Answer: Rainfall occurs when warm air rises in a low pressure area, cooling at higher altitudes due to lower temperatures. Water vapor condenses into droplets, forming clouds, and as droplets grow heavy, they fall as rain. This shows how temperature drives air movement, pressure influences rising air, and water vapor’s condensation leads to precipitation, illustrating their interconnected roles in the water cycle. - Question: Why is monitoring weather conditions important for a country like India, which depends on monsoonal rainfall?
Answer: Monitoring weather conditions in India is crucial as monsoonal rainfall supports agriculture, the backbone of the economy, ensuring food security and livelihoods. Weather forecasts help predict rainfall, manage irrigation, and prepare for droughts or floods, minimizing crop losses and economic impacts, while also aiding disaster preparedness, water management, and planning for millions dependent on seasonal rains. - Question: How does the daily weather report contribute to sustainable living and disaster preparedness in modern society?
Answer: Daily weather reports promote sustainable living by informing people about temperature, rainfall, and humidity, enabling efficient resource use, like water conservation during droughts. They enhance disaster preparedness by forecasting extreme weather like storms or floods, allowing timely evacuations, infrastructure protection, and emergency planning, reducing risks to life and property, and fostering resilience in modern society against climate variability.
Short Questions and Answers
- Question: What is the Earth surrounded by?
Answer: Atmosphere. - Question: How many layers does the atmosphere have?
Answer: Four. - Question: What is the densest layer of the atmosphere?
Answer: Troposphere. - Question: What is the temperature decrease rate in the Troposphere?
Answer: 1°C per 165 meters. - Question: What layer is above the Troposphere?
Answer: Stratosphere. - Question: What does the ozone layer absorb?
Answer: Ultraviolet rays. - Question: Where do meteors burn up?
Answer: Mesosphere. - Question: Which layer aids wireless communication?
Answer: Thermosphere. - Question: What is the most abundant gas in the air?
Answer: Nitrogen. - Question: What percentage of the air is oxygen?
Answer: 21%. - Question: What gas do plants use for photosynthesis?
Answer: Carbon dioxide. - Question: What can excessive carbon dioxide cause?
Answer: Global warming. - Question: What pollutant do automobiles release?
Answer: Carbon monoxide. - Question: What forms when smoke and fog combine?
Answer: Smog. - Question: What is the normal air pressure at sea level?
Answer: 1,013 millibar. - Question: Where does wind flow from?
Answer: High to low pressure area. - Question: What brings rainfall to India?
Answer: Monsoon. - Question: What measures rainfall?
Answer: Rain gauge. - Question: What does weather refer to?
Answer: Short-term atmospheric state. - Question: What does a weather report include?
Answer: Temperature, humidity, rainfall, wind velocity.
Long Questions and Answers (60-70 Words)
- Question: Describe the structure of the Earth’s atmosphere and its layers.
Answer: The Earth’s atmosphere has four layers: the Troposphere, where weather occurs and temperature decreases with height; the Stratosphere, with the ozone layer absorbing UV rays; the Mesosphere, where meteors burn up and temperature decreases; and the Thermosphere, containing ion-particles for wireless communication, with thin air merging into space. These layers vary in temperature, composition, and function, supporting life and atmospheric processes. - Question: Explain the role of the ozone layer and its importance for life on Earth.
Answer: The ozone layer in the Stratosphere absorbs harmful ultraviolet rays from the Sun, protecting life on Earth from skin cancer, allergies, and ecosystem damage. Without it, UV rays would destroy plants, disrupt food chains, and make the Earth uninhabitable. By acting as a shield, the ozone layer ensures a safe environment, supporting biodiversity and the survival of all living organisms on the planet. - Question: Discuss the composition of air and the role of its major gases in supporting life.
Answer: Air is a mixture of gases: nitrogen (78%), oxygen (21%), and carbon dioxide (0.03%). Nitrogen supports plant growth indirectly through soil absorption, oxygen is essential for respiration in humans and animals, and carbon dioxide is used by plants in photosynthesis to produce oxygen, maintaining a balance. This composition ensures life by providing breathable air, supporting plant growth, and regulating atmospheric temperature. - Question: How does excessive carbon dioxide in the atmosphere contribute to global warming, and what are its effects?
Answer: Excessive carbon dioxide traps heat, causing global warming by increasing atmospheric and Earth surface temperatures. This leads to melting ice caps, rising sea levels, and extreme weather like floods and droughts, threatening ecosystems, agriculture, and human settlements. It disrupts the life support system, making climate patterns unpredictable, and poses risks to biodiversity, food security, and global sustainability, requiring urgent mitigation efforts. - Question: Explain how wind movement is caused by atmospheric pressure differences, with an example.
Answer: Wind movement occurs when air flows from high to low pressure areas due to temperature differences. For example, during India’s monsoon, land heats up faster, creating a low pressure area, while the cooler ocean forms a high pressure area. Winds blow from the ocean to land, bringing moisture and rainfall, illustrating how pressure gradients caused by unequal heating drive wind and seasonal weather patterns. - Question: Describe the mechanism of rainfall and its importance for life on Earth.
Answer: Rainfall occurs when warm air rises, cools at higher altitudes, and water vapor condenses into droplets, forming clouds. These droplets grow heavy and fall as rain or snow. Rainfall is vital for life, providing water for drinking, agriculture, and ecosystems, replenishing rivers and groundwater, and supporting plant growth, which sustains food chains, making it essential for the survival of all living organisms. - Question: How do air pollutants from human activities affect health and the environment, and what can be done to reduce them?
Answer: Air pollutants like carbon monoxide from automobiles and sulphur dioxide form smog, causing respiratory diseases, eye irritation, and skin issues, while increasing CO2 leads to global warming, harming ecosystems. To reduce them, we can use electric vehicles, promote renewable energy, plant trees, enforce emission laws, and raise awareness, improving air quality, protecting health, and mitigating climate change for a sustainable future. - Question: Why is the monsoon significant for India, and how does it relate to atmospheric pressure and wind?
Answer: The monsoon is significant for India as it brings rainfall essential for agriculture, supporting food production and the economy. It occurs due to low pressure over heated land and high pressure over the cooler ocean, causing winds to flow from sea to land, carrying moisture. This pressure-driven wind movement ensures seasonal rains, critical for water supply, irrigation, and sustaining millions of livelihoods. - Question: Discuss the importance of monitoring weather conditions and how weather reports benefit society.
Answer: Monitoring weather conditions helps predict temperature, rainfall, and wind, aiding agriculture, travel, and disaster preparedness. Weather reports provide forecasts, enabling farmers to plan sowing, travelers to prepare for conditions, and communities to brace for storms or floods, reducing risks. They promote safety, resource management, and economic stability, ensuring society adapts to changing weather patterns and mitigates the impacts of extreme events effectively. - Question: How does the atmosphere’s composition and structure demonstrate its role in sustaining life on Earth?
Answer: The atmosphere’s composition, with nitrogen (78%), oxygen (21%), and carbon dioxide (0.03%), supports life by providing oxygen for respiration, CO2 for photosynthesis, and nitrogen for plant growth. Its layered structure—Troposphere for weather, Stratosphere with the ozone layer, Mesosphere for meteor protection, and Thermosphere for communication—ensures a balanced climate, shields from UV rays, and enables rainfall, making the Earth habitable for diverse life forms.