Added source if this is the reason why it was downvoted. If not, would love to discuss because I think it’s a very important distinction for understanding mass spec.
Especially as these concepts may be applied to molecules containing more than one chlorine or bromine.
Hey hey,
For sure with all content-related suggestions we ask that source citation be included. This helps ensure smooth sailing on all sides. 
Glancing at the two sources you’ve shared, I certainly see that they discuss mass spec broadly, though if the aim is to clarify ratios and M+2 peak it’s helpful/necessary to include a source specifically for that info.
Could be that I’ve missed it in the sources you linked, and if so please forgive me, though I didn’t at a glance see any reference to ratios (aside from a brief definition/explanation of m/z ratio).
The downvote is mostly there as a placeholder as I’m onboarding a new deck maintainer and I want him to see that I’ve seen the suggestion and put a pause on it (so that he’ll also understand why I’ve done so); it’s not an inherent value judgement about the suggestion as a whole.
Let me know your thoughts and happy to discuss it further.
The ratios specifically come from the discussion of the relative abundance of the isotopes of chlorine and bromine from this KA link, given that the y axis is relative abundance and the ratios will be proportional to the percent abundance listed. The idea of +2 is coming from the difference between 37 and 35 for Cl and 81 and 79 for Br. The idea that the ratio of M:M+2 changes depending on the number of Cl and Br is just from multiplying the probabilities based on relative abundance percentages.
While all of these suggestions can be supported by the KA link. I found that the best walkthrough- summary of these concepts come from these two links:
(For this link scroll to Isotopes and see bromine, vinyl chloride, and methylene chloride)
Thanks for linking those. I’m happy to take a look at those links; I’ll try to squeeze some time in later today.
I’ll take this moment, though, to link back to the submission guidelines just for clarity (particularly the section as to source citation and the kinds of sources we prefer, or less prefer): 📚 AnKing Step Deck Submission Guidelines
In particular, textbooks as citation (aside from MCAT-specific primary sources) are generally considered an unacceptable source. This is for a number of reasons, but the long-and-short of it is to avoid discrepancies, hew to exam-specific resources, and generally to defer to MCAT-particular sources as much as possible. This is a fairly intentional decision that has come about over much time, and consideration (and lots and lots of deck maintenance), for the AnKing team as a whole.
Ideal resources would, probably obviously, include Kaplan, UWorld, Khan, AAMC materials will pretty clearly be the gold standard reference point, and occasionally some less-often-used MCAT-specific resources like the Berkeley books and similar ilk. Without support from one of those resources, or similar, it’s generally (though not always) unfeasible to incentivize content-level changes to the deck as a habit.
I’m also generalizing here, as there are a few suggestions open and this particular one is relatively straightfoward so I don’t mean to imply that the above comments are intended as a downplay across the board. Much of this is to ensure appropriate workflows and deck maintenance as we onboard new maintainers to make sure that the deck stays spritely and healthy and in good hands on an ongoing basis (and, ultimately, to make life easier for both users and suggesters as well as deck maintainers).
I’ll set some time aside, hopefully this afternoon, and give everything else a good look and we’ll go from there.
I definitely understand. In all my other suggestions I’ve stuck exclusively to those resources. I have access to Kaplan, UWorld Qbank, and Khan Academy and couldn’t find a mass spec example for a molecule containing a single chlorine or bromine and multiple. I apologize if I am missing something in those resources. I believe all the suggestions I added can be supported by that one Khan Academy link and some general mass spec/probability knowledge. I just wanted to include those links to make your life a little easier when you were reviewing the suggestions in case you wanted to look at a picture of a mass spectrum for those molecules I was talking about.
It’s possible I haven’t gotten to the question on Uworld yet.
For sure; it’s not meant to be a chastisement at all and, quite honestly, I haven’t been very strict about it in the past but it really is something that we should be more particular about and I have to consider what best-practices will look like/should look like with more maintainers and a team mentality so that has, unfortunately, required me to tighten up certain aspects of deck maintenance.
It’s also not meant to detract from your suggestion as a whole, which have been great and much-appreciated.
It would, of course, be a dream if the AAMC materials were immediately searchable or index-able; that would solve a lot of problems right off the bat. I’m sure someone, far more computer expert than I, could scrape and/or index that material and it would solve a lot of problems for us. Though until then it’s still a bit rag-tag approximating best-practices as much as we can.
I’ll set some time aside this afternoon and try to get caught up on all the suggestions.
Thank you!