In the centre of the atom is the nucleus,
made up of equal numbers of protons and neutrons.
matter is made from small particles called atoms – they are the building blocks of the Universe.
- atoms are so extremely small that one million could fit on the full stop at the end of this sentence. (photo)
- atoms are the smallest identifiable piece of a chemical element. (diagram: Size of atoms)
- many different atom as there are elements. (The Periodic Table of the Elements: poster )
- atoms are mostly empty space with tiny sub-atomic particles (sub-atomic means “smaller than an atom”). (diagram)
- the core of an atom is the nucleus – made two kinds of sub-atomic particle; protons and neutrons.
- swooshing around the nucleus are even tinier particles called electrons. (diagram)
- electrons have a negative electrical charge; protons have a positive charge – electrons are held to the nucleus by electrical attraction. (diagram: electrons / electrical attraction)
- under certain conditions – one atom can be split into more than 200 kinds of short-lived sub-atomic particle of nucleus are made from various tiny particles called quarks. (diagram)
Did you know?
- Quarks – came into existence when the Universe has existed for less than one second. (diagram: quarks / From Quarks to Earth today (poster)
Back to The Universe page.