Why are elements of oxygen family called chalcogens ?

All the elements of oxygen family are

The elements oxygen and sulphur are called chalcogens because

Statement-1: The atomic radii of the elements of the oxygen family are smaller than the atomic radii of the corresponding elements of the nitrogen family. Statement-2: The members of the oxygen family are more electronegative and thus have lower values of nuclear charge than those of the nitrogen family.

Assertion: The atomic radii of the elements of the oxygen family are smaller than the atomic radii of corresponding elements of the nitrogen family. Reason: The members of the oxygen family are more electronegative because they have lower values of nuclear charge, than those of the nitrogen family.

Chalcogens are

All the elements of the oxygen family are radioactive.

Oxygen Family Part-1