The Chalcogens make up group 16 (or group 6A) of the Periodic Table. The name comes from the Greek khalkos (copper) and genos (origin, family), meaning “ore-formers” or “originating from copper”.
Elements of the Chalcogen Group
The elements in this group are:
- Oxygen (O)
- Sulfur (S)
- Selenium (Se)
- Tellurium (Te)
- Polonium (Po)
- Livermorium (Lv) – formerly known as Ununhexium (Uuh)
Among them, Polonium is the only one that is radioactive, while Oxygen is the most abundant and essential for life.
Electronic Configuration and General Properties
All Chalcogens have 6 valence electrons (configuration ns2np4). This gives them the tendency to gain two electrons and form ions with -2 charge in ionic compounds.
The most common oxidation numbers are:
- -2 → in compounds with metals and hydrogen;
- +2, +4, and +6 → in compounds with elements of the same group or with halogens.
Chemical and Physical Characteristics
- Oxygen: colorless gas, essential for respiration and combustion.
- Sulfur: yellow solid, used in sulfuric acid production and fertilizers.
- Selenium: solid with metallic or nonmetallic forms, important in electronics and dietary supplements.
- Tellurium: rare metalloid, used in metal alloys and semiconductors.
- Polonium: radioactive, toxic element with limited use in nuclear heat sources.
- Livermorium: synthetic and highly unstable, produced only in laboratories.
Importance of the Chalcogens
The Chalcogens play a central role in organic chemistry, biochemistry, and industrial processes. Oxygen is vital for cellular respiration and combustion. Sulfur is widely used in fertilizers, medicines, and rubber vulcanization. Selenium participates in antioxidant enzymes in the human body. The heavier elements (Tellurium, Polonium, and Livermorium) have restricted or mainly scientific applications.
FAQ – Frequently Asked Questions about Chalcogens
Which are the Chalcogen elements?
The Chalcogens are: Oxygen (O), Sulfur (S), Selenium (Se), Tellurium (Te), Polonium (Po), and Livermorium (Lv).
Why are they called Chalcogens?
The name comes from the Greek khalkos (copper) and genos (origin). They are called “ore-formers” because many metallic ores contain oxygen and sulfur.
What is the typical electronic configuration of the Chalcogens?
They all have 6 valence electrons with the configuration ns²np⁴.
Which Chalcogen is radioactive?
Polonium (Po) is the only naturally radioactive element of the group.
What are the main applications of the Chalcogens?
Oxygen: respiration and combustion. Sulfur: fertilizers and sulfuric acid. Selenium: electronics and supplements. Tellurium: alloys and semiconductors. Polonium: nuclear sources. Livermorium: only for scientific research.
What is the difference between Chalcogens and Halogens?
The Chalcogens are in group 16 with 6 valence electrons, while the Halogens are in group 17 with 7 valence electrons.