Group 16 CHALCOGENS

Group 16 CHALCOGENS 

Introduction

The group of 16 are known as CHALCOGENS because Sulphur and its congners constitutes most of ores so they are called ore forming materials.
Occurrence
Oxygen is the most abundant elements of all the elements on earth and constitutes about 46% by mass of the earth.
Sulphur exist in the earth to an extent of 0.03%.
To being the only radioactive elements of this family is formed as a decay products as Th and U.

Electronic Configuration

ns2np4 with n=2 to 6.

Atomic and Ionic Radii

Top to bottom the grp atomic size increases due to increases in the no. of new shells.
oxygen have smaller atomic size due to abnormal properties.

Ionization Enthalpies

It decreases down the grp to an increases in the atomic size down the group.

Electron Gain Enthalpy

This are quite high and decreases down the grp due to increases in atomic size. 

 Physical Properties

Oxygen and Sulphur are non metal Se and Te are metalloids and Po is an radioactive mental.

Chemical Properties

The elements of this group react with hydrogen to form hydrides of the type H₂E, where E could be oxygen, sulphur, selenium, tellurium or polonium.

H₂           +           E         →         H₂E
Hydrogen      Group 16         Hydride
                           Element