Sulfur’s amazing structure
Does sulfur exhibit allotropy?
Did you really think sulfur was that simple?
Safety precautions
Attention! All experiments are performed by professionals. Do not attempt.
Process description
Sulfur molecules and crystals can have a variety of structures. Sulfur molecules can contain five atoms (S₅), eight atoms (S₈), or even more. In turn, the same molecules (for example, S₈), like construction toys, can be assembled in different ways: depending on how they are “stacked,” they’ll create solids with different structures. Solid sulfur powder consists of S₈ molecules that are folded in a special way, forming so-called rhombic sulfur. When the powder is heated, a yellow liquid of the same composition is formed. However, excess heat causes some of the molecules to polymerize, forming S₁₆, S₂₄, etc. and creating orange spots. A metal paper clip quickly absorbs the heat, and the sulfur crystallizes immediately. However, the molecules arrange themselves in a different way to how they started, forming so-called monoclinic sulfur. This creates a strong disc with a darker yellow hue than that of the powder. The molecules find this arrangement “inconvenient,” and rearrange over the course of several minutes (scientists call such structures metastable). This causes the disc to brighten noticeably and become so fragile that it is easy to break with three fingers!
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