Carbon. Oxygen. The oxygen in the air that people breathe consists of molecules containing two atoms... Phosphorus. Metalloids exist in a variety of allotropes. Our table of allotropes has over 550 entries covering 63 elements. Charcoal is an allotrope of carbon. Periodic Table of Elements with Names of Allotropes Trends. There are red, gray, and black forms of selenium. Click here to buy a book, photographic periodic table poster, card deck, or 3D print based on the images you see here! For facts, physical properties, chemical properties, structure and atomic properties of the specific element, click on the element symbol in the below periodic table. This is another element with … Among the elements that form allotropes are boron, silicon, arsenic, germanium, and antimony. In the below periodic table you can see the trend of Names of Allotropes. Each entry has a full citation identifying its source.