If a decrease in temperature accompanies a reaction, what occurred? Energy was released.

Energy was destroyed.

Energy was created.

Energy was absorbed.

Which statement is true about a catalyst? a: a catalyst decreases the rate of the reaction. b. a catalyst is consumed during a chemical reaction. c. a catalyst lowers the activation energy of a reaction. d. a catalyst increases the reactant concentration during a reaction.

When a beta particle is emitted, the mass number of the nucleus a. decreases by one b. increases by one c. remains the same d. decreases by two

Analyze the reaction to determine whether the reaction is exothermic or endothermic. explain your reasoning.