Chemistry arrows with horizontal lines below them
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Is the new Chemistry Code book still in production? I am searching for a resource to figure out how to include these horizontal lines under the barbed half arrows. (See attached file.) I located the up-down half barbed arrows on the Chemistry code online at brl.org, but feel that there is very limited information on how to do the rest. What do those horizontal lines represent? Hope to find some help to figure out what to do with them. Thank you!
Hi. I'm not finding the arrows in question. What page are they on?
The "new" chemistry code is still being written. I've been told that APH will produce a print copy of the current (1997) code on demand. Please let me know if that is not the case. Thanks.
Lindy
Hi Lindy,
Please check out my attachment on my second post, Repy #35831, and let me know if the solution I came up with would be accurate or if I need to do something else. Thank you.
Ah, now I see the image you sent. These are valence arrows. The current chemistry code doesn't discuss these in detail and may suggest that they be drawn. Transcribers have come up with different solutions to this problem, and the BANA chemistry committee is working on a recommendation which you may use in your transcription. Describe the symbols in a TN. You may use just the < symbol for the up-pointing valence arrow and just the % symbol for the down-pointing valence arrow. These symbols are to be used only in the context of valence arrows depicted in orbital diagrams. It is not necessary to indicate that the arrowheads are barbed--this is just a print style.
In your book, the arrow pairs are grouped with underlining. Show the grouping by inserting one space between pairs. When only the up arrow appears, the general omission symbol of the Nemeth Code is used to show the absence of the down-pointing valence arrow within the pair. Place element SYMBOLS or orbital level notation as column headings, leaving only one space between columns. I have attached a suggested solution to your example. This should work nicely for you.Lindy
Hi Lindy,
Thank you for answering my questions with a helpful suggestion. I have a couple more questions regarding the valence arrows.
My first question has to do with the blank lines over the 2p, following the valence arrows. Because in your example, you used one separation line under the sp, with one space between the valence arrows, but in the case of blank lines ... do I make two separation lines, or use a space within one separation line?
My second question has to do with the more complex display with the elipses as shown in the attachment. Apparently the elipses are pointing to the various components of the display?
Thank you for your time.
Beth
Beth, I am not familiar with this notation. I'll get back to you after conferring with some chemists.
Lindy
The attached file is something I came up with, but hope to get some feedback within the next couple weeks as the work is due Nov 1.
I put the arrows above blank lines as shown in print and used top cell for those so that the arrows are sitting on them better. And I used dot 5 as guide dots as it appears to be an image of a diagram with labels. Hope this works, but I am open to your recommendations. Someone else is working on part of this book so we're looking for consistency. Thanks!
Beth, you really have me thinking on this one! I "asked my expert" chemist about the significance of the print layout and her answers are copied below, in italics. If I am understanding her correctly, it seems to me that the arrangement of the diagrams is significant, which, to me, points to a good reason to use tactile graphics. By reproducing the drawings, you will not need to try to interpret what they mean. The possibility of giving the wrong interpretation is too risky.
FIRST EXAMPLE (sp and 2p and x's) (I asked "Is there a reason the 2p diagram is raised higher than the sp diagram?") ANSWER: It is important to note that the 2p diagram is raised to indicate that it is a little higher in energy than the sp diagram. The x's may be indicating that there will be other electrons from another atom bonding to that carbon atom that has sp hybridization. That would be my guess based on the little bit of wording that was copied over.
SECOND EXAMPLE (the more complex display) (I asked " Is there significance to the vertical alignment of the energy arrows? That is, are the six configurations related to one another and is that why the text has aligned them in this manner?" ANSWER: The alignment is intentional because the orbitals at the top of the image are highest in energy and the ones at the bottom are lowest in energy. It is also important to keep the ones that have two lines with electron arrows the same because those denote two orbitals that are at the same energy level.
I hope this helps.
Lindy
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