Matter is anything that has mass and occupies space. It is composed of tiny invisible particles. These particles are of different types and sizes. There are three phenomena to verify that matter is made of particles. They are:

1.Diffusion

2.Osmosis

3.Brownian Motion

When a person has left a open perfume bottle in one corner of a closed room, very soon the whole room will have that scent, Why so? It would seem that the perfume particles moved from one corner, where they are in abundance to the entire room, where they are not present. This is called DIFFUSION, and is defined as the net movement of particles from their region of high concentration to their region of low concentration. The path that the particles move along i.e. high concentration to low concentration is called its DIFFUSION GRADIENT.

Elements that have less than eight electrons in its outer shell are not stable, and so they will lose gain or share electrons to have a full outer shell. Elements with one, two or three valence electrons, usually metals, will tend to lose electrons to become positively charged. Elements with five, six or seven valiancy electrons, usually non-metals or metalloids will tend to gain electrons to become negatively charged. Elements with 4-7

valence electrons may share their electrons with one another. A BOND is formed when elements lose, gain or share electrons to obtain a full valence shell. There are three types of bonding:

1.Ionic or Electrovalent Bonding

2.Covalent Bonding

3.Metallic Bonding

This type of bonding occurs when electrons are transferred from a metal to a non-metal. When the element loses or gains electrons, it becomes a positively charged atom called an ion. When an element loses electron, it becomes a positively charged ion called a cation.