Believe it or not, the chemical properties of almost any substance or material in the world depend upon the chemical bonds that make it up. If it weren't for chemical bonds, every material in the world would have to be one of the 118 elements in the Periodic Table. Instead, atoms from these elements bond together to create chemical compounds.

For example, think about table salt. The chemical makeup of table salt is sodium (Na) chemically bonded with chlorine (Cl). Sodium is a hard metal, and chlorine is a greenish gas that can be lethal. When sodium and chlorine bond together, however, they create table salt, a safe substance that we eat every day. There are chemical bonds between the atoms in our bodies (especially the elements carbon, hydrogen, and oxygen), the atoms in the air, and the atoms in most plants and synthetic materials. In fact, chemical bonds are everywhere, and when two elements bond together, their properties often change completely.

From http://www.brighthubeducation.com/science-homework-help/112401-why-are-chemical-bonds-important/