1. WHAT IS THE UNIVERSE MADE OF?
Ans: The stars and clouds in space are made almost 100% of hydrogen and helium, the lightest and simplest elements of all. All the other elements are relatively rare. But some, such as carbon, oxygen,silicon, nitrogen and iron can form important concentrations. This happens in the few rocky planets like Earth, where iron, oxygen and magnesium are the most common elements. Carbon, a scarcer element, is the one on which all
life forms are based.
2. WHAT WAS THE FIRST ELEMENT?
Ans: The first element to form was deuterium – a heavy form of hydrogen. It formed within I.5 minutes of the dawn of the universe.
3. HOW WAS IRON MADE?
Ans: Iron was forged in the heart of super giant stars near the end of their lives, when the immense pressures there forced carbon atoms together.
4. WHAT IS ANTI-MATTER?
Ans: Anti-matter is the mirror image of ordinary matter. If matter and anti-matter meet,they annihilate each other.
Fortunately, there no anti-matter on Earth.
5. WHAT HOLDS EVERYTHING TOGETHER?
Ans: Everything in the universe is held together by four invisible forces. Two of them gravity and electromagnetism-are familiar in everyday life. The other two – the strong and weak nuclear forces are unfamiliar because they operate only inside the invisibly small nucleus of the atom, holding it all together.
6. HOW WERE ATOMS MADE?
Ans: Atoms of hydrogen and helium were made in the early days of the universe when quarks in the matter soup joined
together. All other atoms were made as atoms were fused together by the intense heat and pressure inside stars.
7. WHAT ARE PARTICLES?
Ans: Particles are the basic units of matter that make up everyday objects. There are hundreds of kinds of particles, but all apart from the atom and molecule are too small to see, even with the most powerful microscope.
8. WHAT IS THE SMALLEST KNOWN PARTICLE?
Ans: The smallest particle inside the nucleus is the quark. It is less than 1020 m across, which means a line of ten billion billion of them would be less than a metre long.
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