I am a highly reactive member of Group 1 that reacts violently in water. I have 20 neutrons. what am I?

Based on the position vs. time graph which velocity vs. time graph would correspond to the data

How many moles is 14.5 cm^3 of platinum? the density of platinum is 21.45 g/cm^3.

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.