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Book Review: The Disappearing Spoon by Sam Kean

The Book – The Disappearing Spoon: And Other True Tales of Madness, Love, and the History of the World from the Periodic Table of the Elements

The Author –  Sam Kean

Published on – July 12, 2010

Published by – Little, Brown and Company 

This book can be described as the story telling at its best. The author, Sam Kean describes the evolution of the periodic table with real life stories on how the elements were discovered by their inventors. Kean narrates about the lives of these inventors such as  Marie Curie and Pierre Curie and how their findings impacted on the industry as well as their personal lives. For example, how the  theoretical physicist Maria Goeppert-Mayer facing comparative disadvantages owing to her sex, though she won the Nobel Prize in Physics for her outstanding work.

Then this Pons and Fleischmann story about “Cold Fusion” might be one of the top stories that this book carries.  In 1989, two electrochemistsMartin Fleischmann and Stanley Pons, reported that their apparatus had produced excess heat of a magnitude they asserted would defy explanation except in terms of nuclear processes. Kean describes how this experiment made and unmade Pons and Fleischmann within a few months of time, from being a part of historical scientific breakthrough to being a part of a well-orchestrated con act.  

Pons and Fleischmann with their apparatus of “Cold Fusion” experiment

From “Cold Fusion” story of Pons and Fleischmann, Kean makes his way to introduce pathological science by narrating the story of William Crookes. Due to the grief of the tragic loos of his brother, William Crooks has turned to spiritualism to try to communicate with his brother. He published “Notes of an Enquiry into the Phenomena Called Spiritual” in 1874 and his coworkers thought he was crazy. Crookes eventually left the spiritual research and returned to science and focused on other topics. He finally ends up being a key contributor to the body of knowledge of chemistry.

The theme of each chapter – politics, money, war, the arts, health, toxins, radiation and so on – is prescribed by groups of elements in the periodic table and the things they tell us about the nature of matter; about the stardust origins of the elements; about the compounds they make and why some elements are more reactive than others; and why the table falls into a pattern so obvious that its begetters were able to predict the characteristics of elements not yet identified. The pace is enthusiastic, the tone and language are pitched at the young or the non-chemical and the examples are pleasingly unexpected.

Kean tells the story of Robert Falcon Scott’s expedition to the South Pole. Many scientists were attempting to be the first people to reach the South Pole, but a team led by Roald Amundsen had already reached it. The Amundsen team safely returned from the journey, but Scott’s team was delayed at the pole due to snow flurries and fuel supplies lost due to the high temperatures. Robert Falcon Scott and his companions died on the South Pole.

Kean discusses elements that were put through extreme temperatures to be able to get a sample. Xenon and krypton were put to temperatures as low as −240 F. Kean explains how laser beams are produced by yttrium and neodymium. Kean states that the most powerful laser has more power than the US and it uses crystals of yttrium spiked with neodymium. While lasers produce visible light, masers do not, instead produce microwaves. Masers were considered impossible until Charles Townes worked on them, earning him a Nobel Prize in 1964.

Kean should get the credit for coming up with a book on the subject of chemistry which even a non-chemist can read end to end in a one go due to Kean’s demonstrated ability of top story telling.

Periodic Table Trends

Atomic Radius

The atomic radius of an element is half of the distance between the centers of two atoms of that element that are touching each other. Generally, the atomic radius decreases across a period from left to right and increases down a given group. The atoms with the largest atomic radii are located in group 1 and at the bottom of groups.

Moving from left to right across a period, electrons are added one at a time to the outer energy shell. Electrons within a shell cannot shield each other from the attraction of protons. Since the number of protons is also increasing, the effective nuclear charge increases across the period. This causes the atomic radius to decrease. Moving down a group in the periodic table, the number of electrons and filed electron shells increases, but the number of valence electrons remains the same. The outermost electrons in a group are exposed to the same effective nuclear charge, but electrons are found farther from the nucleus as the number of filled energy shells increases. Therefore, the atomic radius increases.

Ionization energy

The ionization energy or ionization potential is the energy required to completely remove an electron from a gaseous atom or ion. The closer and more tightly bound an electron is to the nucleus, the more difficult it will be to remove, and thus the higher its ionization energy will be. The first ionization energy is the energy required to remove one electron from its parent atom. The second ionization energy is the energy required to remove a second valence electron. The second ionization energy is always greater than the first ionization energy.

Ionization energies increase moving from left to right across a period (deceasing atomic radius). Ionization energy decreases moving down a group (increasing atomic radius). Group 1 elements have low ionization energies because the loss of an electron forms a stable octet.

Electron Affinity

Electron affinity reflects the ability of an atom to accept an electron. It is the energy change that occurs when an electrons is added to a gaseous atom. Atoms with stronger effective nuclear charge have greater electron affinity. Group IIA elements and alkaline earth metals have low electron affinity values. These elements are relatively stable because they have filled “s” sub shells. Group VIIA elements, the halogens have high electron affinities because the addition of an electron to an atom results in a completely filled shell. Group VIII elements, noble gases, have electron affinities near zero, since each atom possesses a stable octet and will not accept an electron readily. Elements of other groups have low electron affinities.

In a period, the halogens will have the highest electron affinity; while the noble gas will have the lowest electron affinity. Electron affinity decreases moving down a group because a new electro would be further from the nucleus of a large atom.

Electro-negativity

Electro-negativity is a measure of the attraction of an atom for the electrons in a chemical bond. The higher the electro-negativity of an atom, the greater its attraction will be for bonding electrons. Electro-negativity is related to ionization energy. Electrons with low ionization energies have low electro-negativities because their nuclei exert a strong attractive force on electrons. Elements with high ionization energies have high electro-negatives due to the strong pull exerted on electrons by the nucleus. in a group, the electro-negativity decreases as atomic number increases, as a result of increased distance between the valence electron and nucleus (greater atomic radius).

Summary of trends

Moving left to right

  1. Atomic radius decreases
  2. Ionization energy increases
  3. Electron affinity generally increases
  4. Electro-negativity increases

Moving top to bottom

  1. atomic radius increases
  2. ionization energy decreases
  3. electron affinity generally decreases
  4. electro-negativity decreases
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Periodic Table Trends

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