The Periodic Table: Learning it the right way!

     I can imagine half of the viewers immediately closing this page by just taking a look at the title, but believe me readers, we've been reading/learning the periodic table the wrong way ever since its introduction to us. The periodic table had taken several turns before arriving to what we see of it today. My fellow chemists would agree that the Modern periodic table wasn't the first to be invented by mankind. The periodic table originated based on "trends". These trends usually depend on the physical properties of the elements or sometimes just a similarity complex. The fundamental classifications started out in several ways.

    From Döbereiner (pronounced as "doo-ba-high-nah") as triads that showed triplets of elements in an arithmetic pattern. The "Octaves" of Newland that arranged elements in sets of eight, just like an octave in classical music theory. I'm pretty sure that any chemist would've come across both of these attempts at classifying the periodic table, but did you know that before Newland's law of Octaves got recognized by the Royal Society in London, there were two other lesser known attempts to classify elements as well? How many of you have come across the "Telluric Screw/Helix" classification and the Lothar-Meyer arrangement? If you've already come across them, leave a comment down below on when you were introduced to them.

    The Telluric Screw arrangement as the name suggests, was the first ever logical periodic classification attempted not by a chemist or a scientist, but rather a French geologist named Chancourtois (pronounced as "shawn-korr-thwa") in 1862. He basically took all the elements that were discovered back then and arranged them helically (45° angled) onto a cylinder on which he drew 16 equidistant perpendicular line owing to the atomic weight of Oxygen (relativity based on Oxygen rather than modern a.m.u that's based on Carbon). He then observed that every 16th element that appeared on the cylinder would coincide with the previous one in the same lines. He also observed that their atomic properties were similar. However, as political as science was back then, his methodology was discarded purely because he was from a geological background.

    The Lothar-Meyer arrangement, unlike The Telluric Screw, received popularity (only because he was a German chemist by the way) in 1869. What Meyer did was rather simple. He plotted a graph between atomic weights of elements (x-axis) and their respective atomic volumes (gram atomic weight divided by density) and created a plot as shown below.

These were his observations:

1. Strongly electropositive elements occupied the peaks of the curve.
2. Less strongly electropositive elements occupied the descending part of the peaks.
3. The Most electronegative elements (halogens) occupied the ascending part of the peaks.

    Based on this information, he also proposed that the physical properties of the elements are a periodic function of their atomic weights and then arranged them in a tabular form accordingly in their increase in weight. So now that we're done with the history lesson, shall we move on? 

    After these 4 attempts at classifying elements, then came the breakthrough from the Russian Chemist, Mendeleev, who needless to say, took the inference of Lothar Meyer to develop what was labelled as the first periodic table. Let us rather not dwell too much into it and skip directly to the Modern periodic table, ignoring his successions, drawbacks and failures.

    The Modern periodic table consists of 118 elements (as of 2021) from Hydrogen(H) to Oganesson(Og) arranged in order as a function of their atomic numbers. As school students, we were either excited or forced to read the elements of the periodic table. I still remember byhearting the first 10 elements in their respective order when I was in 3rd grade. Back then, I did not know what chemistry was, not even what science was in fact. Later, on moving to 6th grade, we were asked to study the periodic table, and students were asked to remember at least the first 30 elements. I could say that all of us, being Chemistry or not, were definitely made to remember a minimum of 20 elements in the periodic order before high school. When I reached high school, I knew the first 50 elements in the order of their atomic number. Proudly, I stepped into college and proceeded to do a major in Chemistry and there arrived the first enlightenment. Even though I had studied 50 elements in their atomic order, it was not of great use, because we barely even studied the first 10 elements in detail in their respective order. The only time they were useful were when I came across periodic trends in detail. But when I studied periodic trends, I also noticed/realized something that changed my entire perception of chemistry and the atomic table. We have been learning it the wrong way since the very beginning! 
    
    The periodic table was never supposed to be learnt from left to right (across periods). That trend was rejected way back in 1860's after Newland's law of Octaves. The right way that we should've learnt the periodic table wasn't horizontally. Instead, it should have been learnt vertically (group-wise). This might seem weird at first, but believe it or not, for a chemist to acquire knowledge about the periodic table, they should rather study it group-wise. There are several reasons as to why one should study it vertically and I believe half of you readers have already realized why. But I'm leaving the following points that support this argument.

1. Reading group-wise allows a student/chemist to understand the similarity amongst the elements in a specific group.

1. It displays the common trend followed using the "Magic numbers" (2,8,8,18,32) which is an atomic number trend that s and p group elements follow (even d group elements do follow, but they start from the second 8 instead).

1. It helps in better understanding of periodic trends, as majority of the trends follow a group-wise similarity.

1. It helps in classification of the periodic table into groups and why they are clubbed together.

1. It also helps in memorizing the entire table easier rather than going straight from 1 to 118 (Leave your methods of remembering elements in the comments down below).

And there are several other advantages apart from this and we'll only realize them if we approach the table in this specific manner of study! 

    The understanding of the periodic table is a crucial factor for a chemist, because when we jump into research, this serves as the first step towards alternative thinking. For example, if you ever were to work in the field of medicinal chemistry and you find out that a certain metal ion (say Sodium) is causing terrible after-effects in the testing species, then only if you've mastered the periodic table, will you ever come up with an alternate metal ion (along Group 1 elements). One can only understand the relativity between Sodium and Group 1 elements if they've studied group-wise similarity of elements in the periodic table. Imagine trying out Magnesium, Aluminum, Silicon etc. and so on only to find out that the alternative was right below the problematic element in the table! 

    The takeaway lesson that I took during my first year of study in college was to learn the periodic table vertically in groups unlike in order of their atomic numbers. Now, you might have a question that I believe could've arose immediately after I began with the periodic trends. Yes. Once you make your fundamentals strong with the group-wise study, the next step is not to proceed period-wise, but rather diagonally. Diagonal relationship is another major factor that is crucial to a chemist learning the periodic table. You MUST master the diagonal relationship once you've mastered the periodic table in groups. This will further allow you to narrow down your solutions in research like the example that I had stated above. The only time where you should prefer learning the table horizontally over the others is when you're learning the f-block elements. Find out why and let me know the answers down in the comments section below.

    Hence, to all my fellow chemists, students and chemistry enthusiasts, learn the periodic table this way and you shall remember/retain knowledge better and you'll never know how much it could be helpful in your future. Please do leave your doubts, questions and concerns in the comments section down below. You could also mail me at decadhya@gmail.com. Have a productive and awesome Monday! Cheers to your Chemistry life😉!