Answer : All of the above are valid expressions of the reaction rate.
Explanation :
The given rate of reaction is,
The expression for rate of reaction for the reactant :
The expression for rate of reaction for the product :
From this we conclude that, all the options are correct.
The parent isotope is cobalt-59 (see the picture below).
The mass number is 59 and atomic number is 27 of the parent isotope.
Neutron activation is the process in which atomic nucleus capture free neutron or neutrons.
Cobalt-60 is produced in nuclear reactors in process of neutron activation from parent isotope cobalt-59 (see the picture below).
Atomic number (Z) is total number of protons and mass number (A) is total number of protons and neutrons in a nucleus.
Cobalt-59 and cobalt-60 are the isotopes of chemical element cobalt.
Isotopes are chemical elements with same atomic number (Z), but different mass number (different number of neutrons).
More about isotopes: brainly.com/question/364529
#SPJ4
