Which one of the following is the strongest base in aqueous solution?

Which one of the following has a square planar geometry?

Which of the following nuclear reactions will generate an isotope?

Consider the reaction, 2A + B $$\to$$ products. When concentration of B alone was doubled, the half-life did not change. When the concentration of A alone was doubled, the rate increased by two times. The unit of rate constant for this reaction is