The Disappearing Spoon Chapter 3

Cory Heavner

Summary of Chapter 3

Chapter 3 is mainly about the creation of the early periodic table and the chemists that contributed to it. The first chemist that this chapter discusses is Robert Bunsen and the many important discoveries that he has attributed to the science. Arguably his most famous invention is the Bunsen Burner, which is a common piece of lab equipment used for controlled equipment, he invented it by taking a regular gas burner and added a valve to increase oxygen flow to provide a single open gas flame (Kean, S., page 49). This is only one of his many contributions to science, another one is spectroscopy, which was extremely important. Bunsen was extremely important in the role of creating the periodic table by taking Dmitri Mendeleev under his wing and being his mentor for many years, giving Mendeleev the tools to become the main contributor to the Periodic Table of the Elements.

Dmitri Mendeleev is known as the father of the Periodic Table by finding elements, giving them a way to be organized in a logical manner, and even predicting what elements that will be discovered in the future. In some cases he was more accurate than the people who actually found them. He also used spectroscopy to find and classify the elements, just like Robert Bunsen. This paragraph goes on to discuss the many scientists that contributed to the Periodic Table and why some are more famous than others.

Elements in Chapter 3

Arsenic (As)

  • Atomic number: 33

  • Atomic Mass: 74.9216

  • Period: 4

  • Group: 15

  • Electron Configuration: 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^3

  • Classified as: metalloid

  • Found: naturally occurs in minerals usually in conjunction with sulfur and metals. Found in a crystalline form

  • Importance: Arsenic is used in poison, medicine, strengthening metals, and preserving wood

  • Discovery: Greek philosopher Albertus Magnus was the first to have Arsenic isolated

  • Characteristics: poisonous, crystalline, and it is the byproduct of Copper and Lead

Gallium (Ga)

  • Atomic Number: 31

  • Atomic Mass: 69.723

  • Period: 4

  • Group: 13

  • Electron Configuration: 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4s^2 4p^1

  • Classified as: Basic metal

  • Found: Mainly present in minerals as a softer metal, a byproduct of zinc

  • Importance: Converts electricity to light, important in Blu-ray technology, found in mobile phones, and is a good alloy with most metals

  • Discovery: discovered in Paris by Paul-Émile Lecoq de Boisbaudran in 1875

  • Characteristics: liquid near room temperature, soft metal like aluminum


  • Atomic Number: 58

  • Atomic Mass: 140.116

  • Period: 6

  • Group: 5

  • Electron Configuration: 1s22s22p63s23p63d104s24p64d105s25p64f15d16s^2

  • Classified as: Lanthanide

  • Found: Found in various minerals, in metallic form

  • Importance: Has the same property as flints, so used commonly in flip lighters, used as pigment, and for flat screen TV’s

  • Discovery: Cerium was first identified by the Jöns Berzelius and Wilhelm Hisinger in the winter of 1803

  • Characteristics: soft metal, tarnishes easy, reacts with water, and it burns when heated

Yttrium (Y)

  • Atomic Number: 39

  • Atomic Mass: 88.906

  • Group: 3

  • Period: 5

  • Electron Configuration: 1s22s22p63s23p63d104s24p64d15s2

  • Classified as: Transition metal

  • Found: in phosphate form with Xenotime, mined in China and Malaysia

  • Importance: alloys, LED lights, and can treat some cancers

  • Discovery: In 1787, Karl Arrhenius came across an unusual black rock in an old quarry at Ytterby, near Stockholm

  • Characteristics: soft, shiny metal, strengthens things in alloys

Ytterbium (Yb)

  • Atomic Number: 70

  • Atomic Mass: 173.043

  • Group: 16

  • Period: 6

  • Electron Configuration: 1s22s22p63s23p63d104s24p64d105s25p64f145d06s2

  • Classified as: Lanthanide

  • Found: Found in the mineral monazite

  • Importance: used in memory devices, tuning lasers, and can be used as an industrial catalyst

  • Discovery: Ytterbium was isolated in 1878 by Jean Charles Galissard de Marignac at the University of Geneva

  • Characteristics: moderately toxic, soft, silvery metal, slowly oxidizes in air

Erbium (Er)

  • Atomic Number: 68

  • Atomic Mass: 167.259

  • Group: 14

  • Period: 6

  • Electron Configuration: 1s22s22p63s23p63d104s24p64d105s25p64f125d06s2

  • Classified as: Lanthanide

  • Found: found in the minerals monazite and bastnaesite

  • Importance: used for pigments, safety goggles, and in fiber optic cables

  • Discovery: In 1843, at Stockholm, Carl Mosander discovered Erbium

  • Characteristics: soft and silvery metal, tarnishes quickly, and is attacked by water

Terbium (Tb)

  • Atomic Number: 65

  • Atomic Mass: 158.925

  • Group: 11

  • Period: 6

  • Electron Configuration: 1s22s22p63s23p63d104s24p64d105s25p64f95d06s2

  • Classified as: Lanthanide

  • Found: in metal form in the minerals monazite and bastnaesite

  • Importance: light bulbs, mercury lamps, and quicker X-rays all use terbium\

  • Discovery: Terbium was first isolated in 1843 by the Swedish chemist Carl Mosander at Stockholm

  • Characteristics: soft, silvery metal, moderately toxic


Royal Society of Chemistry, (2015), Periodic Table, retrieved from

Picture Sources editors, (2016), Dimitri Mendeleev, retrieved



These elements all were important in their own ways. Gallium, which is pretty much the main element in the book, gave this book its title by having a low melting point. Pranksters make spoons out of Gallium, and when they stir the tea they melt and their spoon disappears. All of these elements are at the least moderately toxic to humans, which is important to why these are used. Most of them are used in alloys, which is an important fact about them. And they are all in either period 4, 5, or 6, which is why they are somewhat similar.