In a first-order reaction, the half-life is 139 minutes. What is the rate constant? a. 8.31 x 10-5 s-1
b. 5770 s-1
c. 0.299 s-1
d. 4.99 x10-3s-1
e. 1.20 x 10-4s-1

The characteristic of two different types of reactions are shown below. reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of and element. which statement is true about the atoms of the elements that participate in the two reactions? a: their identity changes in both reaction a and b. b: their identity changes in reaction a but not b. c: their identity changes in reaction b but not a. d: their identity remains the same.