WHEN and WHICH
When can I see a shooting star?
On a night sky, roughly every 15 minutes
Where does the Moon go in the morning?
Nowhere. The Moon is still there, moving around out planet and reflecting the Sun's light.
What are clouds made of?
Millions of tiny water drops or ice crystals.
How many people are there in a world?
7 billion
Why is the sea salty?
Because salt from rocks and soil is taken there by rivers.
Which city has the most people?
Shanghai in China, over 24 million people.
Where is the tallest waterfall?
Angel Falls in Venezuela. 979m high.
What's the point of recycling?
It saves energy and space.
How long does it take to travel the world on a plane?
Atleast 41 hours.
Why is rock hard?
Because it's made of very hard crystal-like pieces, called minerals.
Which star is the brightest in a night sky?
Sirius (the Dog Star)
Where's the hottest place on Earth?
The Lut Desert in Iran.
What is inside of the Earth?
Mixture of solid and liquid rock.
How high can a plane fly?
Up to 13km above ground.
Why is the Earth round?
Because of a force called gravity. Gravity pulls massive objects and the things around them into a round, ball shape.
When do hurricanes happen?
After the summer, when the ocean water is the warmest.
Where do we get electricity from?
Different energy sources. Wind and solar power. The energy is turned into electricity in a power station and travels to our homes along wires.
What happens to all the water people use?
It travels to a sewage works. The water is cleaned in a wastewater treatment facility and released into rivers.
How does lightning happen?
It is a flash of electricity. It happens in storm clouds when raibndrops and hailstones bump and rub against each other.
Why do leaves fall?
Trees make food in their leaves using sunlight, water and air. In the winter there's less sunlight, so many trees drop their leaves and rest until spring. This is how trees gets ready for winter.
When was the first town built?
Around 10.000 years ago.
Where does oil come from?
Deep underground. It's made from tiny sea plants and animals that lived millions of years ago. They died, sank, were covered up by sand and silt and turned to oil.
What makes a volcano erupt?
Gases and liquid rock (magma) from deep inside the Earth. They creep up through the cracks until finally they burst out.
How many countries are there in the World and how many different languages are spoken?
Around 196 countries.
Over 6000 languages.
Why is the sky blue?
Light from the sun is made up of red, orange, yellow, green, blue, indigo and violet. Blue light scatters more than others, so it is the main colour we see.