P1:
To outline the key features of the periodic table, atomic structure and chemical bonding.

Atomic Structure and Periodicity

In modern chemistry and physics it is agreed that the atom is made up of 3 key components: electrons, protons and neutrons. On the periodic table the position of an atom is decided by the number of protons and neutrons in the nucleus of the atom.

The proton, electron and neutron all have different characteristic regarding mass and charge these are as follows: Particle | Relative Mass | Relative Charge | Proton | 1 | +1 | Neutron | 1 | ±0 | Electron | 1/2000 | -1 |

Most of the atom is empty space, 99.9% to be exact. The 0.1% that is made up of the electrons in the shells and subshells. A proton and electron has an equal but opposite charge even though the difference in mass.

Atoms can be identified by their mass numbers and atomic number.

Each element changes depending on the structure, for example Carbon would have an atomic number of 6, and a mass number of 12. The name of the atom changes, if there is a change in protons it becomes a new element. If the number of neutrons changes then a new isotope is created In any element the number of protons is always equal to the number of electrons, unless the atom is an ion. In the period table elements are presented in a box with their atomic symbol, name, mass number, and atomic number. It is commonly displayed like this:

When the number of neutrons in an atom changes it becomes an isotope. This is where the structure of the nucleus has been changed, only a few different isotopes are stable and others can then become radioactive to try and regain stability. Examples of a well know isotope is carbon; this can exist in 3 different isotopes 12C6, 13C6, and 14C6. Each of these has the same number of protons but a different number of neutrons therefore the atomic mass has