An atom is the very smallest particle that still the elements properties. All the atoms of an element are alike. They are also different from the atoms of all other elements. For example, atoms of gold are always the same. It does not matter if they are found in a gold nugget or a gold ring. All gold atoms have the same structure and properties. For example, all gold atoms contain 79 protons. One of golds unique properties is that it is a great conductor of electricity. Gold is a better conductor of electricity than copper. Gold is more rare and expensive than copper. Copper is used in house wiring. Gold is far too expensive. 
What are atoms and their characteristics?
An atom is a tiny metal object