Select all of the following that would act to make the value of k become larger. A. The temperature of the reaction is decreased.
B. The reactant has many sites for a successful collision to occur.
C. A catalyst is used which acts to lower the activation energy for the reaction.
D. The mobility of the molecules is decreased so that there are fewer collisions.
E. The reaction is heated.
F. The concentration of the reactant is increased.

Agroup of students is studying convection current. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other is in an area with warm air. after 10 minutes, the balloon are released from a height of 1 meter. which of the following to the students most likely observe? a) the warm balloon expands and rises. the cold balloon shrinks and sinks b) the balloon both rise. the cold balloon is larger than the warm balloon c) the cold balloon expands and rises. the warm balloon shrinks and sinks d) the balloon rise at the same rate. both balloons are the same size