$F_2$ is formed by reacting $K_2MnF_6$ with:

The element that does not show a variable oxidation state is:

Which of the following reacts most slowly with nitric acid?

Photographic films or plates have ......... as an essential ingredient.

Affinity for hydrogen decreases in the group from fluorine to iodine. Which of the halogen acids should have the highest bond dissociation enthalpy?

The correct order of acidic strength is $.......?$