Chapter 3

The Galapagos of the Periodic Table - Patricia Summers

Synopsis

In Chapter 3: The Galapagos of the Periodic Table, Sam Kean first speaks of Bunsen, his invention of the Bunsen burner, his work with arsenic and his development of the spectropscope. Kean then goes on to talk about the creation of the periodic table. He tells how 2 scientists shared the Davey Medal for their work on the periodic table. Kean tells how Mendelev, one of these scientists, created a periodic table with blank spaces for the elements not yet discovered. He even predicted the weight of these elements; his prediction for gallium was correct! Kean then goes on to describe the lanthonide elements and how difficult they were to discover. Next, Kean tells a story of how a young trickster escaped the death penalty by claiming that he could make porcelin. Because feldspar is used to make porcelin, this lean Kean to speaking about Ytterby and the discovery of Ytterbium, Yttrium, Terbium, and Erbium.

Arsenic

Atomic number: 33
Atomic mass: 74.9246
Period: 4
Group: 15
Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p³
Classification: metalloid
Naturally occurring?: Yes, inorganic compounds and organic compounds. Inorganic compounds of arsenic are found in soil, groundwater and sediments (CDC, 2009). Organic compounds of arsenic are found in fish and shellfish (CDC, 2009). Arsenic is normally found in these compounds: arsenopyrite (FeAsS), orpiment (As₂S₃), realgar (As₄S₄) (CDC, 2009).
Why is it important?: Inorganic arsenic used to be used for pesticides, paint and wood preservatives. Now, it is forbidden because long-term exposure to inorganic arsenic is linked to causing cancer, skin disease, high blood pressure and diabetes (CDC, 2009). Gallium arsenide is used in LED’s (Arsenic, 2016). Arsenic is added to geranium and silicon to make transistors (Arsenic, 2016).
Discovered where, by who?: Arsenic was first found by Albertus Magnus in 1250 (Live Science, 2013).
What is it named for? Arsenic is derived from the latin word "arsenicum" and the Greek word "arsenikon" (Live Science, 2013).
Unique Characteristics:
  • Usually steel gray, but can also be yellow or black (Live Science, 2013)
  • Brittle (Live Science, 2013)
  • Poisonous (Live Science, 2013)
  • Melting Point: 817 C when at the pressure of 28 atmospheres. Arsenic sublimates at regular pressure (Arsenic Element Facts, 2012).
  • Boiling Point: 603 C (Arsenic Element Facts, 2012)
  • 23 Isotopes (Arsenic Element Facts, 2012)

Gallium

Atomic number: 31
Atomic mass: 69.723
Period:
4
Group: 13
Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹
Classification: Metal
Naturally occurring?: Not by itself
Found where?: Naturally found in a salt in zinc and bauxite rocks (Gallium, 2015).
Why is it important?: Gallium is mainly used in semiconductors. Gallium also has many medical uses such as cancer treatments, reduces inflammation, treats infections, may be used in the future to cure cystic fibrosis and malaria. Liquid gallium is also used to create a reflective bright surface on glass (Gallium, 2015).

Discovered where, by who?: Gallium was discovered by Paul Emile François Lecoq de Boisdaudran in 1975 using Brunson's spectroscope (Chapter 3, page 54)
What is it named for?: Gallium was originally named eka-aluminum by Brunson meaning beyond aluminum (Chapter 3, page 53). However, it was renamed by Lecoq de Boisbaudron to Gallium which means France in latin (Chapter 3, page 54)
Unique Characteristics:

  • Gallium melts at 84 F so it’s liquid in your hand (about 98 F) (Chapter 3, page 54)
  • Gallium is a “grainy, thick pseudoquicksilver” (Chapter 3, page 54)
  • Gallium expands by 3.1 % when it becomes a solid (Gallium Element Facts, 2012)
  • Melting Point: 29.76 C (Gallium Element Facts, 2012)
  • Boiling Point: 2200 C (Gallium Element Facts, 2012)
  • 24 Isotopes (Gallium Element Facts, 2012)

Cerium

Atomic number: 58
Atomic mass: 140.116
Period: 6
Group: Lanthanide
Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f²
Classification: Transition metal
Naturally occurring?: Cerium does not occur freely, but it is found naturally in minerals (Cerium Element Facts, 2012).
Found where?: Cerium is found in minerals such as allanite, bastnasite and monazite (Cerium Element Facts, 2012).
Why is it important?: Cerium is used as flints in cigarette lighters. Cerium is also used in self-cleaning ovens (Royal Society of Chemistry, 2015). Currently, scientists are studying Cerium to determine if it can be added to diesel fuel and reduce emission gasses. Cerium is also used in flat-screen TVs, low energy lightbulbs and floodlights (Royal Society of Chemistry, 2015).
Discovered where, by who?: Cerium was found by Axel Cronstedt in 1751 in Vestmanland, Sweden (Royal Society of Chemistry, 2015).
What is it named for?: Cerium is named for the asteroid Ceres which is named after the Roman god of agriculture (Royal Society of Chemistry, 2015).
Unique Characteristics:
  • Tarnishes easily (Cerium Element Facts, 2012)
  • Reacts with water (Cerium Element Facts, 2012)
  • Burns when heated (Royal Society of Chemistry, 2015)
  • Makes sparks when struck (Royal Society of Chemistry, 2015)
  • Melting Point: 798 C (Cerium Element Facts, 2012)
  • Boiling Point: 3443 C (Cerium Element Facts, 2012)
  • 30 Isotopes (Cerium Element Facts, 2012)

Yttrium

Atomic number: 39
Atomic mass: 88.9059
Period: 5
Group: 3
Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹
Classification: Transition metal
Naturally occuring?: Yttrium-89 is the only naturally occurring isotope (10)
Found where?: Yttrium is found in rare earth minerals such as monazite which can be found in Brazil, Australia, Canada and the United States (Yttrium, 2016).
Why is it important?: Yttrium is used to make alloys of other metals. It is also used in lasers and superconducting materials. Superconducting materials are materials that have no resistance to the electric current that flows through them. (Yttrium, 2016)
Discovered where, by who?: Yttrium was found in Ytterby by Johan Gadolin in 1794 (Yttrium, 2016).
What is it named for?: Yttrium is named after where it was found; Ytterby. (Chapter 3, page, 62)
Unique Characteristics
  • Relatively stable in air (Yttrium, 2012)
  • Y⁺³ in compounds (Yttrium, 2012)
  • Soft, silvery metal (Yttrium, 2012)
  • Ignites in air when heated (Yttrium, 2012)
  • Melting Point: 1525 C (Yttrium, 2012)
  • Boiling Point 3340 C (Yttrium, 2012)
  • 25 Isotopes (Yttrium, 2012)

Ytterbium

Atomic number: 70
Atomic mass: 173.054
Period: 6
Group: Lanthanide
Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴
Classification: Transition metals
Naturally occuring?: Ytterbium does not occur in nature by itself (Ytterbium, 2012).
Found where?: Ytterbium is found in minerals such as monzanite (Ytterbium, 2012).
Why is it important?: Ytterbium is used in portable x-ray machines that do not require electricity. Ytterbium is also used to “monitor ground deformations caused by earthquakes and underground explosions” (Ytterbium, 2012). Ytterbium is also used in engraving (Ytterbium, 2012).

Discovered where, by who?: Ytterbium was discovered in Ytterby (Chapter 3, page 62) by Jean Charles Galissard de Marignac in 1878 (Ytterbium, 2012).

What is it named for?: Ytterbium is also named for Ytterby (Chapter 3, page 62)
Unique Characteristics

  • Moderately toxic (Ytterbium, 2012)
  • Ductile (Ytterbium, 2012)
  • Malleable (Ytterbium, 2012)
  • Tarnishes quickly (Ytterbium, 2012)
  • Reacts in water (Ytterbium, 2012)
  • Melting Point: 824 C (Ytterbium, 2012)
  • Boiling Point: 1200 C (Ytterbium, 2012)
  • 30 Isotopes (Ytterbium, 2012)

Erbium

Atomic number: 68
Atomic mass: 167.259
Period: 6
Group: Lanthanide
Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹²
Classification: Transition metal
Naturally occurring?: Not freely, but in minerals (Erbium, 2012).
Found where?: Erbium is found in monazite, bastnasite, xenotime and euxenite (Erbium, 2012).

Why is it important?: Erbium is used in nuclear reactor control rods because it absorbs neutrons. Erbium also turns glazes and glasses pink. Erbium reduces the hardness of metals when it is used in alloys. Erbium also absorbs infrared light, so it is useful in photographic filters. Finally, Erbium is used in the lasers for the removal of acne scars, moles, tattoos and warts (Erbium, 2012).

Discovered where, by who?: Erbium was found in Ytterby (Chapter 3, page 62) by Carl Gustaf Mosander in 1843 (Erbium, 2012)

What is it named for?: Erbium is named after the place it was found: Ytterby (Chapter 3, page 62)
Unique Characteristics:

  • Melting Point: 1530 C (Erbium, 2012)
  • Boiling Point: 2860 C (Erbium, 2012)
  • Moderately toxic (Erbium, 2012)
  • Bright (Erbium, 2012)
  • Soft (Erbium, 2012)
  • Malleable (Erbium, 2012)
  • Slowly tarnishes in air (Erbium, 2012)
  • Slowly reacts with water (Erbium, 2012)
  • Er⁺³ in compounds (Erbium, 2012)
  • 31 isotopes (Erbium, 2012)

Terbium

Atomic number: 65
Atomic mass: 158.925
Period: 6
Group: Lanthanide
Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f⁹
Classification: Transition metal
Naturally occuring?: Terbium does not naturally occur on its own (Terbium, 2012).
Found where?: Terbium is found in minerals such as monazite, zenotime and euxenite (Terbium, 2012).
Why is it important?: Terbium is used in lighting for TV screens. Terbium is also used in the Euro bills to protect against counterfeiting. It can be used in alloys to create magnets that work even at high temperatures. These magnets are used in electric cars and wind turbines (Terbium, 2012).
Discovered where, by who?: Terbium was found in Ytterby (Chapter 3, page 62) by Carl Gustaf Mosander in 1843 (Terbium, 2012).
What is it named for?: Terbium was named for Ytterby (Chapter 3, page 62)

Unique Characteristics:

  • Melting Point: 1360 C (Terbium, 2012)
  • Boiling Point: 3220 C (Terbium, 2012)
  • Moderately toxic (Terbium, 2012)
  • Malleable (Terbium, 2012)
  • Ductile (Terbium, 2012)
  • 4+ ions, not 3+ (Terbium, 2012)
  • Does not tarnish fast in air (Terbium, 2012)
  • Can be cut with a knife (Terbium, 2012)
  • Terbium has 2 allotropes and changes between them at 1289 C (Terbium, 2012)
  • 26 isotopes (Terbium, 2012)

Summary

By reading Chapter 3 and looking at each of the 7 elements mentioned, you can learn just how much our world relies on elements. Without them, we wouldn't have medicine, technology or even colored glass. Technology is constantly evolving thanks to elements such as Gallium, Cerium, Ytterbium and many others. It's amazing how much elements we have never heard of change our world. We owe a lot to the founding fathers of the periodic table and all those who discovered the elements on it.

Chapter 3 Quiz:

Sources