What are allotropes?
In essence, allotropy or allotropes pure elements that exist in two or more different physical forms.
The most notable examples of an allotrope are the allotropes of carbon. The various physical forms of carbon include diamond and graphite.
Allotropes are different STRUCTURAL forms of an element as the atoms of the element are bonded together in a different manner.
Keep in mind, allotropy refers only to different forms of an element WITHIN THE SAME PHASE!