Which of the following is always true about radioisotopes? a) they have unstable nuclei. b) their neutron-to-proton ratio is 1: 1. c)their decay products are stable isotopes. d) all of the above  the answer is a , i just passed my test.

Which of these describes the rate of this chemical reaction? h2 + cl2 → 2 hcl a. an increase in the concentration of hcl and h2 with time b. an increase in the concentration of hcl with time c. an increase in h2 and cl2 with time d. a decrease in hcl and cl2 with time