Which of the following statements is true about the structure of an atom? 1. The proton and neutron are of equal mass.
2. The electron is the most massive subatomic particle.
3. The electron cloud contains more mass than the nucleus.
4. The nucleus of an atom contains more mass than the electron cloud.
A
1 and 4
O
2,3, and 4
O
1 only
2 and 3

How does a catalyst increase the speed of a reaction? a. the catalyst eliminates the activated complex stage, allowing products to form immediately. b. the catalyst lowers the energy level of the reactants, making it easier for them to react. c. the catalyst makes it easier for the activated complex to form, lowering the activation energy. d. the catalyst raises the energy level of the products, making the reaction finish sooner. reset next