Oxygen differs from the other elements of the group. Compounds of oxygen with metals are more ionic in nature and hydrogen bonding is more important for oxygen compounds. Oxygen is never more than divalent beacasue when it hs formed two covalent bonds, there are no low energy orbitals which can be used for form. further bonds. However, the elements S,Se,Te and Po have empty d- orbitals which may be used for bonding, and they can form four or six bonds by unpairing electrons. The higher oxidation states become less stable on decending the group.
The bond between S and O, or Se and O, are much shorter than might be expected for a single bond owing to `rho pi - dpi` interaction between the p- orbital of oxygen and d- orbital of S or Se.
Which one of the following orders represents the correct order for the properties indicated against them?

Options

A. `H_(2)O lt H_(2)S lt H_(2)Se lt H_(2) Te -` "acidic character"
B. `H_(2)O lt H_(2)S lt H_(2)Se lt H_(2) Te -` "thermal stability"
C. `H_(2)S gt H_(2)Se lt H_(2) Te lt H_(2)O -`"reducing character"
D. `H_(2)S gt H_(2)Se lt H_(2)O lt H_(2)Te -`"boiling point "

Explanation

To solve the question regarding the properties of oxygen and its group elements (S, Se, Te, Po), we will analyze the properties mentioned in the video transcript step by step.

### Step 1: Acidic Character
- **Observation**: The acidic character of the hydrides increases down the group from H2O to H2Te.
- **Reason**: As we move down the group, the bond strength between hydrogen and the central atom decreases due to the increasing size of the central atom. This results in a weaker bond that can more easily release H+ ions, thus increasing the acidic character.
- **Conclusion**: The correct order for acidic character is: H2O < H2S < H2Se < H2Te.

### Step 2: Thermal Stability
...