The periodic table is made up of different elements in different areas. For example, Carbon, Oxygen, Hydrogen, Helium, Fluorine, etc etc. These elements can be classified into several groups such as the mighty noble "element-ness"-or also known as noble gases, halogen gases, alkali metals, transition metals, etc etc.
Let me ask you one question: Is CO2 (carbon dioxide) an element or molecule?
The answer is obvious isn't it? Carbon dioxide is NOT the element. It is the molecule. But carbon and oxygen are elements because you cannot divide them more finely without destroying them. The same applies to H2O (water).
Literally, element Definition: A chemical element is a substance that cannot be broken down by chemical means. If you do break it, the element would not be the same and the completely new element emerge. Elements are defined by the number of proton they possess.
Atom Definition: An atom is the defining structure of an elements. In other words, atom is the structure that determines an element, in which it cannot be broken by any chemical means. A typical atom consists of a nucleus of proton, electron and neutron.
118 neutrons, 79 protons and 79 electrons.
Further explanation: I mentioned before about atom is the structure that determines elements. We know that atom consist of subatomic particles (proton, neutron and electron). If Au atom (from above example) is bombarded with something and then the proton number change from 79 to 78, is it still Au atom? The answer is NO. Changing the proton number results in changing the elements. Thus, elements have different properties because the number of sub-atomic particles in their atoms differs.
"For each element, its geography is its destiny." (Kean, 2011)
