Wednesday, 28 March 2012


Atoms are the building blocks of matter. They are everywhere from your shoes to the water that you drink. They are very small, so small that they are not visible to the naked eye.  Atoms are made out of three main particles: Neutrons, Protons and Electrons.  These particles are very important and give the atom its properties.

In an atom you have a nucleus which consists of protons and neutrons. Around the nucleus you have electrons which whizz around the nucleus. The electrons are arranged in shells or energy levels around the Nucleus. For the first 20 elements the lowest energy levels are filled first. Only a certain number of electrons are allowed in each shell. The first shell has 2 electrons, the second shell has 8 electrons and the third shell has 8 electrons.

Protons have a positive charge, electrons have a negative charge and neutrons have a neutral charge. In an atom there is the same amount of protons as electrons meaning that the overall charge of the atom is neutral. There are always one or two more neutrons then protons in an Atom. If the atom has a charge it is known as an ion. If there are more protons(positively charged) then electrons then the atom is a positive ion but if there are more electrons(negatively charged) then protons then the atom is a negative ion.  

1 comment:

  1. Oh really? I always thought the nucleus of an atom contained protons and neutrons. A fundamental error on the first line of the second paragraph. Such a shame.