ATOMS AND IONS

Atoms are the basic unit of chemistry. They consist of 3 smaller things:

• Protons - these are positively charged (+)
• Electrons - these are negatively charged (-)
• Neutrons - these have no charge

These 3 smaller particles are arranged in a particular way. In the center is the Nucleus where you find the positive Protons and neutral Neutrons.
In orbit around the nucleus are the Electrons. These are found in a series of orbits (depending on the atom) with differing numbers of electrons as seen below.

Interaction of Atoms
It's the electrons in orbit around the nucleus that allow one atom to interact with other atoms so they can be linked together.
For example, H2O consists of an Oxygen atom linked to 2 Hydrogen atoms. The linkage or interaction between the electrons of the Hydrogen and Oxygen atoms is called a Chemical Bond. More on these later.
Atoms in the Human Body
The human body is made up of a couple dollars worth of chemicals.
The 12 most useful atoms for you to know about are listed below:

Ions

Sometimes atoms gain or lose electrons.  The atom then loses or gains a "negative" charge. These atoms are then called ions.

• Positive Ion - Occurs when an atom loses an electron (negative charge) it has more protons than electrons.

• Negative Ion - Occurs when an atom gains an electron (negative charge) it will have more electrons than protons.

The following image shows Na losing an electron and Cl gaining an electron

• Thus the Na becomes Na+
• The Cl becomes Cl-

Here are some examples of common ions:
Na+	Sodium
K+	Potassium
Cl-	Chloride
Ca+	Calcium
Fe+	Iron
P-	Phosphorous