• What’s the sea made of?
  The sea is water with oxygen, carbon dioxide, nitrogen and various ...

• What is cellulose?
  Cellulose is a natural fiber, found in the walls of all plant cells. ...

• What’s the air made of?
  Pure air is 78.9% nitrogen, 20.95% oxygen. There are traces of argon ...

• How do things dissolve?
  When solids dissolve in liquid, it may look as if the solid ...

• How many elements are there?
  New elements are discovered every so often, but the total number ...

• What is nuclear fusion?
  Nuclear energy is released by fusing or joining together small atoms ...

• What is the heaviest element?
  The heaviest is hahnium. It has 105 protons and 157 neutrons in its ...

• What is nuclear fission?
  Nuclear fission releases nuclear energy by splitting big atomic ...

• What are the transition metals?
  Transition metals are the metals in the middle of the periodic table, ...

• What’s the fastest thing in the Universe?
  Light, which travels at 300,000 km (186,000 miles) per second. This ...