Extra 20 important long questions and answers from Chapter:15 Air Around Us of Class 6 Science (CBSE):-
1-10 Long Questions
1. What are the main components of air?
Answer: Air is a mixture of different gases. Its main components are:
Nitrogen (78%)
– The largest component, helps in plant growth.
Oxygen (21%)
– Essential for respiration and combustion.
Carbon Dioxide (0.03%)
– Used by plants for photosynthesis.
Water Vapor
– Affects humidity and weather patterns.
Inert Gases (Argon, Neon, etc.)
– Present in small amounts.
Dust and Smoke Particles
– Can cause pollution and affect health.
2. What is the importance of air?
Answer: Air is essential for life and many natural processes:
Breathing (Respiration)
– Oxygen is needed by humans and animals to survive.
Photosynthesis
– Plants take in carbon dioxide and release oxygen.
Combustion
– Oxygen supports burning of fuels.
Wind Energy
– Used for generating electricity and sailing boats.
Weather and Climate
– Water vapor in air forms clouds and rain.
Sound Transmission
– Air carries sound waves to our ears.
3. How does the oxygen cycle maintain balance in nature?
Answer: The oxygen cycle ensures a continuous supply of oxygen in nature:
Plants produce oxygen
during photosynthesis.
Animals and humans use oxygen
for breathing.
Oxygen is used in combustion
of fuels.
Decomposers use oxygen
to break down dead organisms.
Oxygen dissolves in water
, supporting aquatic life.
The cycle continues
, maintaining balance in the atmosphere.
4. Explain the nitrogen cycle.
Answer: The nitrogen cycle helps maintain nitrogen levels in nature:
Nitrogen gas
in the air is not directly usable by plants and animals.
Nitrogen-fixing bacteria
convert nitrogen into useful compounds.
Plants absorb nitrogen
from the soil to make proteins.
Animals eat plants
and get nitrogen for body functions.
Decomposers break down
dead plants and animals, returning nitrogen to soil.
Nitrogen is released back
into the air, completing the cycle.
5. What are the causes of air pollution?
Answer: Air pollution is caused by various human and natural activities:
Smoke from industries
releases harmful gases.
Vehicle emissions
add pollutants like carbon monoxide.
Burning of fossil fuels
increases carbon dioxide levels.
Deforestation
reduces oxygen supply and increases carbon dioxide.
Agricultural activities
use chemicals that pollute air.
Natural causes
like volcanic eruptions and wildfires add dust and gases.
6. How does air pollution affect human health?
Answer: Air pollution has serious health effects:
Respiratory diseases
like asthma and bronchitis.
Heart problems
due to exposure to toxic gases.
Eye and skin irritation
caused by smog and dust.
Weakened immune system
from harmful pollutants.
Reduced oxygen supply
in high pollution areas.
Long-term exposure
can lead to lung cancer and other diseases.
7. How does air pollution affect the environment?
Answer: Air pollution damages the environment in many ways:
Acid Rain
– Polluted air forms acids that harm plants and water bodies.
Global Warming
– Excess carbon dioxide increases Earth’s temperature.
Ozone Layer Depletion
– Harmful gases cause ozone thinning.
Harm to Wildlife
– Polluted air affects animals and birds.
Reduced Crop Yield
– Toxic gases damage plants.
Water Pollution
– Pollutants settle in rivers and lakes.
8. What is the role of the ozone layer?
Answer: The ozone layer protects life on Earth in the following ways:
Absorbs harmful UV rays
from the Sun.
Prevents skin cancer
and other health issues.
Regulates temperature
and maintains climate balance.
Supports plant growth
by filtering excess radiation.
Protects marine life
, as UV rays can harm aquatic organisms.
Ozone depletion
by CFCs weakens this protective layer.
9. How does wind help us in daily life?
Answer: Wind is useful in many ways:
Generates electricity
through wind turbines.
Helps in sailing
boats and ships.
Pollination of plants
by carrying seeds and pollen.
Brings rain
by moving clouds.
Cools the surroundings
on hot days.
Used in drying clothes
and agricultural products.
10. How do humans contribute to air pollution?
Answer: Humans contribute to air pollution in many ways:
Burning fossil fuels
for transport and electricity.
Cutting down forests
, reducing oxygen levels.
Releasing industrial waste
into the air.
Using plastics
that release harmful gases.
Agricultural activities
like burning crops.
Overuse of chemicals
in industries and farming.
11. How do plants and animals depend on air?
Answer: Air is essential for both plants and animals in various ways:
Oxygen for breathing
– Animals and humans use oxygen for respiration.
Carbon dioxide for photosynthesis
– Plants absorb CO₂ to make food.
Pollination
– Air helps in transferring pollen from one flower to another.
Seed Dispersal
– Some seeds are carried by the wind to grow in new places.
Regulates temperature
– Air helps maintain Earth’s climate balance.
Moisture for growth
– Water vapor in air provides moisture for plants and animals.
12. What is the importance of water vapor in the air?
Answer: Water vapor plays a key role in maintaining Earth's weather and climate:
Helps in cloud formation
– Condenses to form clouds, leading to rainfall.
Regulates humidity
– High water vapor increases moisture in the air.
Prevents excessive heating
– Traps heat and keeps the Earth warm.
Supports plant life
– Plants absorb moisture from the air for survival.
Affects weather patterns
– More water vapor can lead to storms and rainfall.
Essential for the water cycle
– Evaporates and returns as rain, completing the cycle.
13. How does air pressure affect weather?
Answer: Air pressure plays an important role in weather changes:
High air pressure brings clear skies
– Indicates stable weather.
Low air pressure brings storms
– Leads to strong winds and heavy rains.
Changes wind patterns
– Winds blow from high to low-pressure areas.
Affects temperature
– Low pressure often brings warmer temperatures.
Helps in cloud formation
– Low pressure helps water vapor to rise and condense.
Influences ocean currents
– Changes in air pressure can cause oceanic weather changes.
14. Explain the process of cloud formation.
Answer: Clouds are formed due to condensation of water vapor in the air:
Sun heats up water bodies
– Water evaporates and rises as vapor.
Water vapor cools
– As it rises, it reaches cooler air in the atmosphere.
Condensation begins
– Water vapor turns into tiny droplets.
Tiny droplets combine
– They form visible clouds in the sky.
Clouds move with wind
– Can travel long distances before releasing rain.
Rain falls
– When droplets become too heavy, they fall as precipitation.
15. How does deforestation affect air quality?
Answer: Cutting down trees leads to various air quality problems:
Reduces oxygen levels
– Fewer trees mean less oxygen production.
Increases carbon dioxide
– Less CO₂ absorption leads to higher air pollution.
Causes climate change
– More CO₂ leads to global warming.
Increases dust in the air
– Trees prevent soil erosion and dust storms.
Reduces rainfall
– Trees help maintain moisture in the atmosphere.
Harms wildlife
– Many animals lose their natural habitat due to deforestation.
16. How is wind formed?
Answer: Wind is formed due to differences in air pressure:
Sun heats the Earth unevenly
– Some areas get more heat than others.
Warm air rises
– It creates low pressure in that area.
Cool air moves in
– It creates high pressure in cooler areas.
Air moves from high to low pressure
– This movement is called wind.
Faster pressure change means stronger winds
– Strong winds can cause storms.
Wind patterns help control climate
– Winds bring rains and change temperatures.
17. What is smog and how does it affect us?
Answer: Smog is a mixture of smoke and fog, harmful to living beings:
Forms in cities
– Due to vehicle exhaust and industrial pollution.
Reduces visibility
– Thick smog makes it hard to see.
Causes breathing problems
– Leads to asthma and lung diseases.
Irritates eyes and skin
– Can cause redness and allergies.
Harms plants and animals
– Blocks sunlight and damages crops.
Increases global warming
– Contains greenhouse gases that trap heat.
18. How do factories control air pollution?
Answer: Factories use different methods to reduce pollution:
Install filters
– Chimney filters remove harmful smoke particles.
Use eco-friendly fuels
– Natural gas and renewable energy reduce pollution.
Reduce emissions
– Advanced machines release fewer pollutants.
Plant trees nearby
– Trees absorb carbon dioxide and improve air quality.
Follow pollution control laws
– Governments enforce strict pollution norms.
Recycle waste
– Reduces smoke and toxic gas emissions from burning.
19. What are the effects of global warming on the air?
Answer: Global warming affects air and climate in many ways:
Increases temperature
– Hotter climate due to excess CO₂.
Melts polar ice caps
– Causes rising sea levels.
Changes rainfall patterns
– Some areas get more rain, others dry up.
Increases natural disasters
– More storms, cyclones, and heatwaves.
Reduces air quality
– More heat leads to more smog.
Affects wildlife
– Animals struggle to survive in extreme temperatures.
20. How can we reduce air pollution?
Answer: There are many ways to reduce air pollution:
Use public transport
– Reduces vehicle emissions.
Plant more trees
– Helps absorb carbon dioxide.
Use renewable energy
– Solar and wind power reduce pollution.
Reduce waste burning
– Burning plastics and garbage causes smoke pollution.
Stop using plastic
– Plastic releases harmful gases when burned.
Spread awareness
– Educating people helps in controlling pollution.
