Communicating Data with Periodic Tables

I think periodic tables might just be the most ubiquitous infographic. I have zero data to back up this assertion. It’s just something that chemists use all the time, and most chemists I know tend to have one handy at a moment’s notice, or decorate their offices with them. They never seem to have just one. Even chemistry classrooms tend to have more than one, so I think it’s worth considering the periodic table’s ability to communicate information. Some periodic tables are pretty sparse. Some are hugely information dense (here’s a favorite of mine). And, as a recent article in C&EN points out, although there’s a common shape, there isn’t even a consensus on the “one true way” to arrange a periodic table.

Last May I found this periodic table while browsing through old books in my university’s library.

Periodic Chart of the Elements from inside cover of Gaines, Binder & Woodriff, 1951.

Periodic Chart of the Elements from inside cover of Gaines, Binder & Woodriff, 1951.

It’s from a 1951 textbook (Gaines, Binder & Woodriff), so it’s not terribly surprising that there are fewer elements (96 instead of 118) and some of the symbols have changed (e.g. A for argon, Fa for francium, Cb for columbium, which was later renamed niobium). What made it jump out to me at the time is the arrangement of the table itself: what I’m used to seeing in the middle of the table as the d-block is wrapped around in doubled rows. Copper, silver, and gold are in the same column as lithium, sodium, and potassium! 15 rare earths (La-Lu) are noted in a single cell, but not identified individually, and elements 89-96 are incorporated into the table, rather than segregated on an island of misfit actinides.

I’m told this arrangement was common in the Soviet Union. That it appears in an English-language textbook in 1951 seems interesting, and I wonder if it became less common in the US as the Cold War carried on.

What has struck me since that first look are the choices the creator of this table made about which information to include about each element, and how it’s presented.[1] We have atomic numbers, symbols, atomic weights, and the number of electrons in each shell. But, wait, there’s more: small text at the top of the table explains the horizontal lines running through the table cells:

  • “% area below dotted lines indicates relative ability to lose electrons”
  • “% area above broken lines indicates relative ability to gain electrons”

First, I’m curious now what method or measurement they used to rate ability to gain/lose electrons. Since they are relative quantities, I wonder what they are relative to? (I suppose it’s time to go back to the library and take another look at that old textbook.)

Second, I think the use of the different line styles to convey relative values is a neat trick. They are subtle, yet distinct, and they’re even read from opposite ends of the table cell (area above vs area below). Look along the fourth row (K→Ni) and watch the dotted line drop. You can see the periodic trend in ability to lose electrons! And using the same table you can see the trend in ability to gain electrons!

Several textbooks I’ve used have included figures with the periodic trends as 3D column charts. I don’t love them. 3D charts are really difficult to read because the depth or apparent volume tends to distort the actual differences in size. As a physical object I’d bet they’re useful (like these 3D-printable models), but as an image on a page or screen, I’m not enthused. The periodic table shown above, though, shows two of those trends clearly in a single figure. (Even those 3D printed models show only one trend at a time.) That’s pretty cool.

[1]: As you might guess, I’m a fan of Edward Tufte’s The Visual Display of Quantitative Information.

The Bus

"The last student who went to graduate school after working with me was hit by a bus," my research advisor said to me as I began to figure out what I'd do after graduation with a Bachelor's degree and a desire to work in industry. He has an odd sense of humor, and I took the comment as a reminder to keep my eyes open and not get wrapped up in my head. This same advisor had encouraged me to apply to graduate programs, warning me that it would be hard later to "take the vow of poverty" after an industrial-sized paycheck if I decided to pursue a PhD after a few years on the job.

I didn't know the first thing about the graduate school application process and wasn't even sure where to apply. He encouraged me to set my sights high, nudged me toward higher profile programs and, in retrospect, he also guided me away from programs that I later learned had reputations for treating their students poorly. I was accepted at multiple schools thanks to his efforts, my letter writers, and the good advice I got about writing personal statements.

Skip ahead three years and his voice is in my ear, though it's only a memory speaking: "the last student … was hit by a bus." I cross the street like I'm five. Look left-look right-look left. All clear. I'm going to finish this thing and I will not become a pancake.

It's not until another year later, maybe two, that I hear something different as the memory speaks: "the last student stepped in front of a bus."



Oh no.

I don't know the story. I never knew the other student, but I can't unhear this version of the story now. And I understand it in a different way: Be careful, and Come back safe, okay?

During graduate school I learned about my anxiety, and I experienced the emotional quicksand that is depression. I felt sad for no apparent reason. Blue. Down. There were days I was unmotivated to leave home. Days when the failures of my research felt like failures of my self. And I realized one day that my predecessor had probably felt the same way.

I wish I could reach back through time and tell him that depression lies. But I can't. It doesn't work that way.

So I'll tell you: Depression lies. Don't carry that burden around alone. You are worthy of love and worthy of help.

And please, for the love of whatever you hold dear, be careful crossing the street. Come back safe, okay?

Professoring by the Golden Rule

My internal clock is perpetually off. I am very, very good at arriving 5 minutes late. Reminders and alarms help, but they aren't a cure.

I am also an Olympic-level procrastinator. Something due at noon? I may finish at 11:57 that morning. (If it didn't rank high enough on my to-do list, I may have started at 11.) More than once I have stayed up late (or, in some cases, gotten up early) to finish something I ought to have done weeks before.

So when a student arrives to class late, or scribbles down the last of their homework just before handing it in, I don't get mad. It doesn't seem fair to judge them for behavior I also exhibit. (Pot, meet Kettle.) I try to set reasonable expectations for workload and due dates. I try to be forgiving when they miss class, or forget to come to a meeting. Because I have also had to miss class, and I have also forgotten meetings, and I have also had to respond to unexpected events in my life that were out of my control. Sometimes I am the person asking for their understanding.

I try to teach by following a form of the Golden Rule:

Expect of others what you would have them expect of you.

I see it as an act of mercy. Some of my colleagues call it coddling. "They need to be prepared for The Real World! In the Real World you'd be fired. In the Real World blah blah blah!"

They're already in the real world. They're holding down jobs, and some have kids of their own. They're participating in service, and active in athletics. They're people with responsibilities, hobbies, and demands on their time and attention. I am not the only influence in their lives. My class is not the most important thing in their lives.

And I can live with that.

Level up!

The spring semester was rough. I was constantly going full-tilt and couldn’t find time to stop and breathe. This fall couldn’t be more different, though I’m busier than ever. I’m teaching an overload (15+ contact hours), wrangling four research students on three separate projects, picking up more service work for the department and university, and chasing a toddler at home. Yet somehow I feel more like I’m surfing on top of the wave of work and not getting dragged down into it. I've joked that I’ve leveled up from “well, nothing's on fire, so it must be fine” to “I got this.” In short: I feel competent.

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Conferencing with an infant

I went to the ACS Mid-Atlantic Regional Meeting (MARM) at the beginning of June, and, since she’s still nursing and refuses to take a bottle, Sweet Pea came along. My husband did not. The conference was Sunday to Tuesday, and he wasn’t able to take Monday and Tuesday off. Sweet Pea has a wonderful daycare, but we still don’t have a babysitter, and arranging family to babysit was a challenge because of distance and scheduling. So I just took her along and spent three days solo parenting.

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All work and no play

I spent the fall semester on maternity leave. My daughter arrived in August, a new and wondrous source of joy in my life. I needed weeks to recover physically from the stresses of childbirth, and months to figure out what my life looks like with another little person in it. The first few times the three of us (my baby, my husband and I) left the house, it felt like an endeavor. The first time I took Sweet Pea out on my own was a monumental challenge. With time and practice, it’s all gotten easier. You can get used to almost anything if you do it enough – like wake up in the middle of the night every night for months.

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Academic Time-Savers: Text Entry on a Mac

Meghan Duffy tweeted a CHE article by Anne Curzan about using (or overusing) em dashes, which led a few folks on Twitter to point out ways to type a true em dash (— instead of --, for example). On an iOS device, you can simply press and hold the hyphen to get a pop-up list of other dashes. On a Mac, you can hold the shift and option keys (some know option as the alt key) while typing a hyphen. But you have to remember which key combo to press, and if your habit is to type --, it can take a long time to get used to Shift+Option+-.

Making your own shortcuts

If you don’t want to relearn the keys you’re pressing, you don’t have to. You can make your own shortcut so that when you type -- it becomes —. The best part of this trick is that it applies well beyond em dashes. You can use text shortcuts like this one to save yourself time in all kinds of ways.

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Identity change

When I got married, I changed my last name. I was very attached to my maiden name, and couldn’t bear to let go of it completely, so I dropped what had been my middle name, took my maiden name for my new middle name, and finished off my new signature with my husband’s last name. 

I’ve been Mrs. (and now, Dr.) Haas for about seven years. I’m content with my name change choice. I’m content with the way my identity has changed.

Now it’s changing again.

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Molecular tug-of-war: A hands-on demonstration of molecular polarity

Last fall I taught polarity in a different order than I have before. In every previous class, I introduced polarity in the VSEPR unit: first bond polarity, and then molecular polarity immediately after. Instead, last semester, I introduced bond polarity after Lewis structures and tried to get the students in the habit of identifying polar bonds and drawing dipole moments for those bonds alongside their Lewis structures. Then, after working through VSEPR theory, we brought polarity back into the mix. Anecdotally, they seemed to have a better sense of which bonds were and were not polar in the 3D molecules than my previous classes. (I don't know that the order of topics improved their understanding. I suspect it's simply a matter of having had more time to "digest" the idea and practice it more in 2D before moving to 3D.)

Even though they were quite good at identifying polar bonds, the students still had trouble identifying polar molecules. Specifically, they used the simple rule of thumb that if the bonds were polar, the molecule had to be polar, which fails when the symmetry of a molecule is such that the polar bonds all cancel out (e.g. BF3 or CF4).

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Where does it end?

I listened to some of the inaugural episode of "Late Night with Chemjobber" last night. As a whole, I think it was a decent start. There were some technical issues (the audio cut out several times), some glitches (at one point Chemjobber accidentally hung up on the callers), and I get the feeling that nobody involved was practiced at radio or podcasting. All of that was understandable. For the most part, the topics were interesting or amusing, and (after a little dancing about deciding who should respond first) generated good discussions. I have one bone to pick with the show, though, and it's a big one: significant air time was given to a troll. 

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A Lab Notebook for Teaching

Chemists are trained to use lab notebooks, whether paper or digital, to record their observations, measurements and preliminary conclusions. Good lab notebooks include not just what you tried, but why you tried it and even what expectations you had for the outcome. Lab notebooks are a record; reading over previous entries can help you notice patterns and plan future experiments. Someone else should be able to read your notebook and understand what, why & how you did everything. Ideally, they could reproduce your work with that knowledge.

Teaching involves a lot of experimentation: choosing examples, refining explanations, developing ways to address misconceptions, rearranging the order of topics, yet few professors I know keep a teaching notebook, even among scientists who would surely defend the importance of a notebook in lab.

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Geoff Marcy recently resigned from Berkeley after word got out that he’d been a serial sexual harasser of women in astronomy, that a Berkeley investigation concluded he had violated campus conduct policies, that the university had barely even slapped his wrist for it, and that the women in astrophysics (and the rest of the sciences) were sick of this same old crap.

Okay then. One down, more to go.

Marcy is not the last harasser. His resignation does not mark the eradication of this disease. There are more creeps out there. There are more people making science and unwelcome place. We’re not done.

Hearing about Marcy, his misdeeds, and his shield of privileges and achievements, I was reminded of another creep, one I could have called out, but didn’t. I feel guilty hearing about these cases. I know of sexual harassment in science that has gone unreported. Am I, by staying silent, complicit?

I will tell you the story, but I am not prepared to name names. I am not the victim, and I have no wish to bring her unwanted attention. I wasn’t even present when it happened, but when a person tells you of her harassment, you’d better believe her. It’s been over a year, but that doesn’t make his actions any less wrong.

Last year at a conference I attended, a graduate student, who I’ll call Annie, was groped by a senior professor, who I’ll call Jack. It was the last night of a week-long conference. There was a party, with dancing and booze. Jack was on the dance floor. Annie walked by him, and he grabbed her butt. As Annie’s companions emphasized, this was not a case of “accidentally” bumping into or brushing up against someone. This was a middle-aged man grabbing a young woman in a clearly sexual way. Annie and her companions left the party immediately, unwilling to risk more time in an unwelcome space.

I heard about the incident moments later from Annie and the other junior scientists (grad students & post-docs) who had seen it happen. My initial response was shock: He did what?! My next thought was discouragement and disappointment. It had been a pretty great week: I’d learned about exciting science, had some great conversations, and met some delightful people. But Jack’s inability to keep his hands to himself tarnished my impression of the conference. And – even though it didn’t happen to me, and I hadn’t been in the room – it made me feel unwelcome.

We didn’t report Jack. We talked about it, the group of us. Who would we tell? Jack wasn’t just an attendee; he chaired the conference. The best we could foresee was one of our advisors just saying ‘steer clear.’ So we said nothing. The conference was over, anyway. What was the harm?

The harm is that Annie is almost certainly not the first woman Jack has grabbed. She probably won’t be the last. Annie and Jack are at different institutions in different cities, but we’re all in the same field. We’re likely to cross paths again. Even if those of us who know about his harassment of Annie warn others away, Jack just becomes another open secret.

Jack made our group feel unwelcome at the conference party. Who else is he pushing out? What if Jack is harassing women in his own department? Who is listening to them?

You might say “It’s not so bad. He just grabbed her butt, it’s not like he really did any damage.” Except it is that bad. Someone is getting pushed out every time. And it’s damaging for every single woman. It shouldn’t have to take four women multiple years to get a man to keep his hands to himself.

Jack has a name, and a home department, and a publication list as long as my arm. Jack has a reputation and a position of privilege that far outweighs mine, or Annie’s. I can’t fight that battle right now, even though I feel guilty for letting another creep skate by. So the guilt buzzes in my ear when I hear these stories, and it reminds me that I need to do better next time – and that, sadly, there is likely to be a next time.