Which of the following is Lewis base?

Which from following is a soft metal?

What is the order and molecularity respectively for the elementary reaction given below?

$$ \mathrm{O}_{3(\mathrm{~g})}+\mathrm{O}_{(\mathrm{g})} \longrightarrow 2 \mathrm{O}_{2(\mathrm{~g})} \text { if } \mathrm{r}=\mathrm{k}\left[\mathrm{O}_3\right][\mathrm{O}] $$

Identify the property of colloidal solutions so that colloidal particles move freely towards respective electrodes under an applied electrical potential.