Which group 16 element combines with hydrogen to form a compound that has the strongest hydrogen bonding between its molecules?
(1) oxygen (3) sulfur
(2) selenium (4) tellurium

The group 16 element which combines with hydrogen to form a compound that has the strongest hydrogen bonding between its moleculen is is oxygen. This fact can be observed from the boiling points of the hydrides of the elements of group 16. For instance, the boiling point of hydrogen sulphide is - 60 degree celcius,that of hydrogen selenide is - 41.2 degree celcius, hydrogen telluride boiling point is - 2.2 degree celcius while that of water is 100 degree celcius. These bioiling points proof that the intermolecular hydrogen bond between the molecules of hydrogen and oxygen are the strongest.

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Ametal with a large number of free flowing electrons most likely has good conductivity