It's easy for Americans to forget that the food they eat doesn't magically appear on a supermarket shelf.

While using energy from sunlight, plants turn carbon dioxide into food in a process called photosynthesis.

Alkali metals such as sodium, potassium, rubidium, caesium and francium are extremely reactive elements, just putting them in water can result in an explosion! They are carefully stored in oil to prevent this happening.

While aluminum is the most common metal found in the Earth's crust, the most common metal found on Earth is iron, mostly because it makes up such a large part of the Earth's core.