The half-life of a radioactive isotope is 2.4 minutes. If you started with 100.0 grams, how many grams would be left after 7.2 minutes has elapsed? Explain how you arrived at your answer.

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

14 days is the half-life of phosphorus-32

i think it's c. if you look search electronic symbol on google and then click on wiki it shows you a

i'm wiling to try and you : )