[Chemistry Class Notes] Group 16 Elements Pdf for Exam

It is interesting to note that certain elements behave like oxygen. In other words, these elements exhibit properties and trends similar to those of oxygen. The members of such a collective group are known as Group 16 elements. Let us see the similarities between oxygen and the other members of this group. We shall also understand why oxygen is an important member of this group.

For convenience sake, we can call this group as the chalcogen family. This family consists of elements found in group 16 of the periodic table. It is essential to remember that periodic tables are an arrangement of elements with similar properties. The chalcogen family is placed under the oxygen classification. Now, these chalcogens are considered as the leading group 16 elements. The elements in this group are – oxygen, sulphur, selenium, tellurium, and polonium. Ref Fig.1.

What are Chalcogens? 

Chalcogens is the name given to periodic table group 16 elements or V1. This group consists of oxygen, sulphur, selenium, tellurium, and polonium. When we call them elements, it is essential to note that oxygen is a gas while other group members are solids. Oxygen and Sulphur are available in pure form while other elements occur as ions in metal ores. O and S form oxides and sulphides. 

All elements of this group have isotopes with varying stability. The elements of this group and their compounds vary in their toxicity. O and S are essential to all forms of life. Compounds of selenium, tellurium, and polonium can be hazardous. Selenium is a trace element and can cause disorders. Tellurium compounds have not been known to cause a human fatality. Polonium and its compounds are radioactive, extremely toxic, and need to be handled with care.

About Chalcogens 

The chalcogens or the oxygen group is placed in column 16 of the periodic table (ref fig 1). It has elements of oxygen, sulphur, selenium, tellurium, and polonium. You may find one more element, livermorium. The chemical symbols for these elements are- O, S, Se, Te, PO, and Lv. The first four elements of this group are known as chalcogens or ore-forming elements. The reason is that a majority of metal ores found in the Earth’s crust are sulphides or oxides.

You know that oxygen is the most freely found element in nature. It forms 20.946 percent of air and 46.6 percent of the world’s mass generally in the form of silicates, carbonates, oxides and sulphates. We need oxygen to breathe.  

Group 16 Elements 

All group 16 elements are closely related to human life.  

Oxygen – chemical notation of oxygen is O. It is a colourless and odourless gas. We inhale oxygen and exhale carbon dioxide. Trees exhale oxygen. Oxygen combines with many elements to form their oxides. 

Sulphur – the chemical symbol for sulphur is S. It is found in combined as well as the isolated state. In seawater, the percentage of sulphur is 0.09. A large amount of sulphur is found in underground deposits. 

Selenium is a rare element. Selenium is found in free as well as in combination with heavy metals such as lead, silver, and mercury in some minerals. Selenium is most stable in grey metallic form. 

Tellurium is an element that has properties between metals and non-metals. It is one of the rarest stable elements found on earth. It is located in compounds with copper, lead, silver, and gold. Tellurium is also found in a free state. 

Polonium is a radioactive element or isotope in the group 16 elements. It has scientific applications for alpha radiations as it is a radioactive element. It is also a rare element.