Tim Johnstone, of Ilam school, asks :-

Is there anything smaller than an atom?

Rodger Sparks, a physicist with the Institute of Geological and Nuclear Sciences, responded.

The answer is yes, because an atom itself is made out of things that are smaller still. The three kinds of things that atoms are made of are called protons, neutrons and electrons. The protons and neutrons are stuck together in a tiny lump we call the nucleus, while the electrons go buzzing around them in a kind of cloud. The cloud of electrons makes the outside of the atom, and the nucleus is a very tiny speck right in the middle.

To understand how small an atom and its nucleus is, imagine that we magnify an atom a thousand, billion times until it was 50 metres across. Even then the nucleus would be only as large as a grain of sand. This is quite amazing, because it means that atoms are really mostly empty space. And because everything is made of atoms, including us, it means that all the things we can see and touch are mostly empty space too.

Scientists who study the nucleus of the atom have recently found that the protons, neutrons and electrons are themselves made of even smaller particles. We dont know much about them yet but scientists have fun while unravelling such mysteries of nature.