Basic Particles

The structure of an atom is made up of three basic parts:

• Protons - positively charged particles which are present in the nucleus, or center of the atom
• Electrons - negatively charged partices which "orbit" the nucleus
• Neutrons - neutral particles present in between the protons in the nucleus

As in all of science like charges attract, thus it is only natural that electrons stay in their orbit because of that attraction. Under normal circumstances there is a parity of electrons and protons because their charges, negative and positive respectively, are equal in force. In contrast, similar charges repel forcing all of the electrons away from each other. Thus they force other electrons into different orbitals. The neutrons function in the atom is to impair repultion of protons in the nucleus. Because protons are in such close proxsimity unlike electrons, protons require the neutrons to help hold the nucleus, and thus the atom, together.

Orbitals

There are many theories of how an electron orbits the atom. Neil Bohr put out probably the simplest theory which is refered to as Valance Shell Theory. He stated that electrons have certain orbital tendencies depending on the number of electrons present in the atom. For intstance, a helium atom has two electrons which exist in the same orbit, but the next electron added is forced into a different orbital. Each orbital has a specific number of electrons it can hold, and each orbital must be filled in a certain order. The orbital names and the number of electrons they can hold are:

1. s - 2
2. p - 6
3. d - 10
4. f - 14

The actual order is shown on the Periodic table section. It is just important to note that the electrons are what actually cause the bonding between different or similar elements. These orbitals also have a unique shape that, though unimportant at this level will become very important the deeper you look into chemistry. The shapes are:

• s - sphere
• p - dumbbell
• d - 4 tear drops

Radioactivity

Radioactivity is feared by many people, but it is not commonly known the most powerful type of radition usual can't go through a sheet of paper. There are five main types of radiation and each has different properties.

• Alpha Particles - Nucleus of a Helium Atom
• Beta Particles - Electron when expelled converts a neutron to a proton
• Neutrons - Creates a different isotope
• Positrons - anti-electron when absorbed converts a proton to a neutron
• Gamma rays - leaves nucleus with excess energy, has no mass

Alpha particles are the most powerful because they are made up of 2 neutrons and 2 protons. The term "powerful" can be deceiving because it is simply the heaviest of all the particles and thus requires the most energy to expel; however, it can be stopped with a sheet of note book paper because of the particle's large size. Gamma rays on the other hand are not very powerful, but are able to penetrate through many layers of concrete.