Chlorine is often used to kill bacteria in our pools, homes, hospitals, etc. It has nothing to do with Chlorophyl which is a set of organic chemicals that help plants and bacterias photosynthesis process. Other than of course the horrible pun.
Finches are of course Birds and have a vast variety of subspecies. It was Finches of the Galapagos that helped Darwin formulate the Origins of Species. Argon is the second Nobel gas we have got to with this series. As with most of the novel gasses, it’s inert and doesn’t react with anything unless under certain conditions. We have a not insignificant amount of it in the air we breathe every day. It was by the discovery of Lord Rayleigh that we found out that Argon existed. Lord Rayleigh studied birds, finches, seabirds, etc. in his studies of how the atmosphere moves. Thus we have the connection to the humble Finch.