Here's a breakdown of their properties:

* Carbon (C): Found in Group 14 of the periodic table, carbon is a versatile element with numerous allotropes (different forms) such as diamond, graphite, and buckminsterfullerene. It's essential for life and forms the backbone of organic molecules.

* Sulfur (S): Located in Group 16 of the periodic table, sulfur is a yellow, brittle solid that's found naturally in its elemental form. It's used in various industries, including the production of sulfuric acid, a vital chemical.

* Iodine (I): Residing in Group 17 of the periodic table, iodine is a purplish-black solid that sublimes (changes directly from solid to gas) at room temperature. It's essential for human health, particularly for thyroid hormone production.