Let's solve the worksheet step by step and explain each part clearly.
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Q.1. Fill in the blanks with suitable words.
a) ________ is the mixture of gases that surrounds the Earth.
✔ Answer: *The atmosphere*
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Explanation: The atmosphere is the layer of gases that envelops the Earth, composed mainly of nitrogen (78%) and oxygen (21%), along with trace amounts of other gases like carbon dioxide, water vapor, and argon.
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b) The Earth, our planet, absorbs energy from ________ in the form of solar radiation.
✔ Answer: *the Sun*
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Explanation: The Earth receives energy primarily from the Sun in the form of sunlight or solar radiation. This energy drives weather, climate, and most life processes on Earth.
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c) About 30 percent of incoming solar energy is ________ back into space.
✔ Answer: *reflected*
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Explanation: Approximately 30% of the solar radiation that reaches Earth is reflected back into space by clouds, ice, snow, and other reflective surfaces. This is known as Earth’s albedo.
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d) ________ in the atmosphere, like the glass panes in a greenhouse, lets in sunlight and traps the heat energy escaping from the Earth. As a result, the temperature of Earth ________.
✔ Answer:
- First blank: *Greenhouse gases*
- Second blank: *increases* (or *rises*)
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Explanation: Greenhouse gases such as carbon dioxide (CO₂), methane (CH₄), and water vapor allow visible sunlight to pass through but absorb and re-radiate infrared (heat) radiation, trapping heat in the atmosphere. This natural process keeps Earth warm enough to support life. However, human activities have increased these gases, enhancing this effect and causing global warming.
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Q.2. Write the major greenhouse gases in the spaces below.
From the diagram and scientific knowledge, the
major greenhouse gases are:
1.
Carbon dioxide (CO₂)
2.
Methane (CH₄)
3.
Nitrous oxide (N₂O)
4.
Water vapor (H₂O)
5.
Chlorofluorocarbons (CFCs) *(less abundant but very potent)*
> In the diagram, you can see sources like:
> - Factories and power plants → emit CO₂
> - Cars and airplanes → emit CO₂ and other pollutants
> - Cows and landfills → emit CH₄
> - Fertilizers → emit N₂O
> - Industrial processes → emit CFCs
✔ So, fill in the boxes with:
-
Carbon dioxide (CO₂)
-
Methane (CH₄)
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Nitrous oxide (N₂O)
-
Water vapor (H₂O)
*(Note: Usually, three to four are expected; CO₂, CH₄, N₂O, and H₂O are the main ones. CFCs are also important but less common in basic worksheets.)*
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✔ Final Answers Summary:
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Q.1
a)
The atmosphere
b)
the Sun
c)
reflected
d)
Greenhouse gases,
increases
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Q.2
Greenhouse gases:
1.
Carbon dioxide (CO₂)
2.
Methane (CH₄)
3.
Nitrous oxide (N₂O)
4.
Water vapor (H₂O)
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This worksheet helps understand how the
greenhouse effect works naturally, and how human activities are intensifying it, leading to
global warming.
Parent Tip: Review the logic above to help your child master the concept of greenhouse gas worksheet.
