The half-life of a first-order reaction is $20$ minutes. What is the rate constant (in min$^{-1}$) for this reaction?

The rate constant of a reaction is $k = 3.28 \times 10^{-4}$ s$^{-1}$. Find the order of the reaction.

Which of the following is a water-in-oil type of emulsion?

What is O-O bond length in ozone ?