PowerPoint Peeves and Chemistry Arrows

May 23rd, 2013

ChemBark’s ongoing series on PowerPoint advice continues with a look at another one of my irrational pet peeves: the “fat” reaction arrow.

If you are writing reactions in a text box, chances are you’ll use the “rightwards arrow”, Unicode character 2192 (hex). You will probably also choose a font without serifs, because slide text (including atomic symbols) looks better without serifs. Unfortunately, this is how the rightwards arrow is rendered in many sans-serifs fonts:


I know this is a matter of personal taste, but there is something about that reaction arrow that turns me off. It’s too fat. The same character in Times New Roman looks much better. She has a graceful elegance relative to her Calibri cousin. Consequently, if you want to stick to Unicode characters for writing out reactions, I advocate writing everything in a sans-serif font, then changing the arrow to Times New Roman. You many also need to adjust its font size to make it look right:


And while we’re on the subject of arrows, there is no need to use the double-headed arrow symbol U+2194 (↔) to indicate an equilibrium. Remember, the double-headed arrow typically separates resonance structures. Instead, use U+21c4 (⇄) or U+21cc (⇌). These characters don’t always appear on the maps in Office, but you can copy and paste the symbols into your text. A full listing of arrow characters is here.

7 Responses to “PowerPoint Peeves and Chemistry Arrows”

  1. andre Says:

    “there is no need to use the double-headed arrow symbol U+2194 (↔) to indicate an equilibrium” You can use stronger language than that. It’s flat out wrong to use double-headed arrows for equilibrium. Double-headed arrows are for resonance structures only (in chemistry… I’m sure they might have other uses somewhere).

  2. Trent Wallis Says:

    I like the Royal Society of Chemistry font, available here: http://www.rsc.org/Education/Font.asp

    It has an equilibrium symbol and a plimsoll symbol, both of which are staples for me!

  3. Andy K Says:

    As a HS Chemistry teacher making my notes/presentations for class, I, like you, just could not stand the arrow. Several years ago I set up an auto-correct(Mac OS): –> and will automatically make the appropriate symbol that I want.

  4. prunesmith Says:

    I hate the fat arrow. I was very careful not to use it in my Ph.D. candidacy report!

  5. Anonymous Says:

    That is one of the main reasons I always wrote the equations in ChemDraw

  6. qvxb Says:

    The “unhandsomely fat” rightwards arrow allows me and my fellow OFs (OF = old fellow; G rating) to easily tell that it is an arrow and not a line with an indistinct blob at one end.

  7. kdog Says:

    Linux Libertine has a nice equilibrium arrow (“rightwards harpoon over leftwards harpoon,” U21CC).

    The plimsoll (“circle with horizontal bar,” U29B5) is harder to find. For MS users it’s in Cambria Math. Insert into Word by typing 29b5 then Alt-X. Other typefaces that support this character are listed here:

    The RSC font is nice but the symbols are not at the correct code points.

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