What are O, S, Se, Te, Po commonly called?

Naturally existing sulphates

Naturally occurring SULPHIDES

General electronic configuration

Atomic/ Ionic radii

Ionisation enthalpy
(energy to remove an e-)

Electron gain enthalpy
(energy to gain an e-)

Why is the electron gain enthalpy of oxygen less (-ve) than sulphur?

Electronegativity
(ability to pull an e- pair towards itself)

Metallic character

Radioactive element(s)

Melting and boiling points (trend)

Why is there a large difference between the melting and boiling points of Oxygen and Sulphur?

Oxidation states exhibited

When does oxygen exhibit +2 oxidation state?

Oxidation states of S, Se, Te with O, F

Anomalous behaviour of oxygen is due to...

Why is there strong hydrogen bonding in H2O, but not in H2S?
(H2O is liquid while H2S is gaseous)

Covalency of Oxygen, reason

Hydrides and their trends

Types of oxides

Halides

Stability of halides

stable hexahalides and their structure

Structure and hybridisation of tetrafluorides

Dichlorides, dibromides
Structure, hybridisation

Disproportionation in dimeric halides