Class 5 Science Question Answers - Earth and its Natural Satellites

Q1: What is the Earth's atmosphere, and why is it important?
Ans: The Earth's atmosphere is a layer of air that surrounds our planet. It's important because it protects us from the harmful ultraviolet rays of the sun.

Q2: Describe the three main layers of the Earth's structure.
Ans: The Earth has three main layers:

• Crust: The outermost layer made of rocks where continents and oceans are located.
• Mantle: A layer below the crust, consisting of hard rocks (upper part) and hot molten rocks (lower part).
• Core: The innermost layer with an outer core of molten iron and nickel and an inner solid core made of iron.

Q3: How does an earthquake occur, and what causes it?
Ans: Earthquakes happen when tectonic plates (parts of the Earth's crust and mantle) move and bump against each other at faults. This movement creates seismic waves, causing the ground to shake.

Q4: What is the sun made of, and why is its core so hot?
Ans: The sun is made of hydrogen and helium. Its core is extremely hot because in the core, hydrogen changes into helium through a process called nuclear fusion, releasing a lot of heat and light energy.

Q5: Explain what phases of the moon are and how they change.
Ans: Phases of the moon are different shapes of the moon as seen from Earth. These shapes change because the moon revolves and rotates, and the amount of sunlit part we see varies. It starts with the New Moon, then Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter, and Waning Crescent.

Q6: What causes tides in the oceans and seas?
Ans: Tides are caused by the gravitational pull of the moon on Earth's oceans. This pull creates a bulge or high tide on the side of Earth facing the moon. The sun's gravity also affects tides, leading to spring tides and neap tides.

Q7: What is an eclipse, and what are the two main types of eclipses?
Ans: An eclipse occurs when one celestial object blocks the light from another. The two main types are:

• Lunar Eclipse: When the Earth comes between the sun and the moon, casting a shadow on the moon.
• Solar Eclipse: When the moon comes between the sun and Earth, blocking sunlight from reaching Earth.

Q8: What are artificial satellites, and why are they launched into space?
Ans: Artificial satellites are man-made objects that orbit Earth. They are launched into space for various purposes, including weather forecasting, communication, remote sensing of Earth's surface, and studying outer space.

Q9: Can you name a few Indian satellites and their uses?
Ans: Yes, some Indian satellites include Aryabhata, Cartosat-2, EDUSAT, Bhaskara, Rohini, and INSAT-2A. They are used for communication, weather forecasting, remote sensing, and space exploration.

Q10: What is space travel, and why is it challenging? Can you name some Indian astronauts?
Ans: Space travel is the journey of humans into space. It's challenging because astronauts are exposed to high radiation levels and need extensive training. Some Indian astronauts include Rakesh Sharma, late Kalpana Chawla, and Sunita Williams.