Mini-Essay II - Chemistry, A Volatile History.
Part 2
Kennedy Sawyer
1/7/25
The periodic table of elements stands as one of the most significant achievements in the
history of science. Starting with Dmitri Mendeleev in 1869, it was a groundbreaking moment
that that gave order and substance to the elements, which had puzzled scientists at the time. This
documentary explored the history, importance, and alternate forms of the periodic table,
highlighting its role in shaping our understanding of the natural world.
Before the periodic table's inception, only 55 elements were known. Some early chemists
like Dalton and Döbereiner made significant contributions to the understanding of atomic
weights and chemical properties. Dalton proposed that elements had distinct atomic weights,
while Döbereiner identified triads of elements with similar properties, hinting at a deeper
connection among them. Also, Mendeleev's arranging elements by increasing atomic weight and
grouped them based on their chemical properties. His findings were validated when elements
like gallium were discovered, fitting perfectly into the predicted spaces.
The periodic table is more than just a chart as many of us know it as, it is a map of
chemical relationships. It organizes elements into groups with similar properties, such as the
alkali metals and halogens as talked about. It allows scientists to predict the behavior of elements
based on their position in the table. The organization has many implications for chemistry,
biology, and physics, as it provides a framework for understanding how elements interact and
combine to form compounds and what we can do with them.
Moreover, the periodic table has evolved over time. The introduction of the atomic
number by Moseley in 1913 refined Mendeleev's original model of the periodic table and
establishing a more accurate method for organizing elements although this was not an easy path
with clear direction at some times (Stewart, 2019). This shift from atomic weight to atomic
number helped others to understand the relationships among elements and eliminated
inconsistencies.
While Mendeleev's periodic table is the most recognized, several alternate forms exist
that offer different perspectives on elemental relationships. One example is the long form of the
periodic table, which includes the lanthanides and actinides in a separate block below the main
table (Cao, 2021). This arrangement emphasizes the similarities among these elements, which are
often overlooked in the traditional layout. Another variation is the periodic table of elements by
electronegativity, which orders elements based on their ability to attract electrons in a chemical
bond. This form highlights the trends in reactivity and bonding behavior among elements,
providing valuable insights for chemists (Boeyens, 2008).
The octet rule states that atoms are most stable when they have eight electrons in their
outermost shell (valence shell). This resembles that of the noble gases, which are known for their
chemical inertness. By aiming for a full outer shell, atoms engage in various bonding interactions
that shape the compounds and materials we encounter in the world around us. Understanding this
rule provides insight into why certain elements behave the way they do in chemical reactions.
The periodic table is a testament to the quest for knowledge. From Mendeleev's initial
vision to the modern interpretations, we use today, it has transformed our understanding of the
natural world. By categorizing elements in a meaningful way, the periodic table not only decodes
the building blocks of matter but also serves as a foundational tool.
References:
Boeyens, J. C. (2008). The periodic electronegativity table. Zeitschrift für
Naturforschung B, 63(2), 199-209.
Cao, C., Vernon, R. E., Schwarz, W. E., & Li, J. (2021). Understanding periodic and non-
periodic chemistry in periodic tables. Frontiers in Chemistry, 8, 813.
Stewart, P. J. (2019). Mendeleev’s predictions: success and failure. Foundations of
Chemistry, 21, 3-9.
BBC Chemistry - A Volatile History: Episode 2 The Order of the Elements . YouTube.
JDR. (2016, December 16). https://www.youtube.com/watch?v=37Mrhf7IfbI&t=12s
