Beginner Topic 653 of 1102 Inorganic Chemistry
Oxygen Family
Group 16 elements, or chalcogens, include oxygen, sulfur and selenium.
In-depth explanation of Oxygen Family
Group 16, the chalcogens, comprises oxygen, sulfur, selenium, tellurium and polonium, each with six valence electrons in the ns2 np4 configuration. Oxygen is highly electronegative and forms a strong double bond in O2, with a bond energy of about 498 kJ/mol, and it also exists as ozone. Sulfur forms rings and chains and is the most important element of the group after oxygen. The common oxidation states are -2, +4 and +6. Hydride acidity rises down the group because the H-E bonds weaken, so H2Te is a stronger acid than H2S, which is stronger than H2O.
Going deeper: Oxygen Family
Key ideas: Group 16 ns2 np4: O, S, Se, Te, Po. O is the most electronegative after F and shows mostly -2 and in peroxides -1. S, Se, Te can have +2, +4, +6. H2O is a liquid, but H2S is a gas, owing to hydrogen bonding in water. Acid strength of hydrides rises down: H2O less than H2S less than H2Se less than H2Te, as bond length grows. First electron gain enthalpy of O is less negative than that of S.
Common mistakes and connections: A typical mistake is expecting O to show positive states or expanded octets; it cannot. Another is thinking electron gain of O is largest; the small size causes repulsion, so S has the highest in the group. Links to oxides, sulfur chemistry, ozone and hydrogen bonding.
Visualization of Oxygen Family
Electronegativity falls from oxygen (3.5) to sulfur (2.6) across Group 16, so oxygen forms the strong double bond and the group becomes more metallic. The interactive lesson shows this as a live animation or chart.
Worked example and use case
Hydrogen telluride, H2Te, is a stronger acid than hydrogen sulfide, H2S.
Frequently asked questions about Oxygen Family
What is Oxygen Family?
Group 16 elements, or chalcogens, include oxygen, sulfur and selenium.
Is Oxygen Family a beginner, intermediate or advanced topic?
Oxygen Family is a beginner topic in Inorganic Chemistry. It needs no earlier chemistry lessons and is a good starting point.
What should I learn before Oxygen Family?
Study these earlier topics in Inorganic Chemistry first: Phosphorus Allotropes, Phosphoric Acid, Fertilizers.
What comes after Oxygen Family?
The next topics in Inorganic Chemistry are Ozone and Oxides.
Can I practise Oxygen Family with quizzes?
Yes. The interactive lesson includes a self-check question on Oxygen Family, and the Inorganic Chemistry quiz draws on every topic in this area.
Where Oxygen Family fits in Inorganic Chemistry
Oxygen Family is topic 38 of 113 in Inorganic Chemistry.