Which of the following statements is/are true? 1. For a reaction to occur the reactant molecules need to collide in the right orientation with sufficient energy 2. The units of the rate constant for a second-order reaction are M1 time 1. 3. The order of a reactant can be determined by the stoichiometric coefficient of that particular reactant. 1 and 2 I only 2 only O 3 only 1.2. and 3