May 25, 2015

#04-022: Mendeleev and the Periodic Table

black-and-white photo of a man in profile; long white hair and beard, almost wizard-like; hands clasped in front of him
Dmitri Mendeleev

Note: If you've ever studied chemistry, you've benefited from the efforts of Mendeleev, a great (and largely unsung) Russian scientist.

Get Ready: Have you ever studied chemistry? If so, did you use the "Periodic Table of the Elements"? What is it used for?

Dmitri Mendeleev (1834-1907) is not exactly a household name. Yet most students in the world, and certainly all chemistry students, have benefited from this Russian chemist's work.

Mendeleev is the creator of what became the periodic table of the elements. Previous chemists had recognized groups of the elements (the most basic forms of matter--hydrogen, oxygen, carbon, and so on). But it was Mendeleev whose overall scheme won the day. It was so good that later scientists using his table were able to predict the properties of various elements. Mendeleev himself predicted the properties of eight elements unknown in his time.

It should be pointed out that the type of image we see in science textbooks and classrooms today was not Mendeleev's work. Instead, it is a graphic representation of his ideas, created by an American named Horace Groves Deming in 1923.

A typical Periodic Table of the Elements
Click here for a larger, more complete, clickable version

The basis of Mendeleev's work is something called "chemical periodicity" (hence the name "periodic table"). This is all very complex, but it is based on increases and decreases in the properties of atoms, like how much energy they need in order to remove an electron, or how close the centers of two atoms of the same type can get.

Mendeleev was the youngest of many brothers and sisters. Some sources say there were 11, 13, 14, or even 17! His father, a teacher, went blind and lost his position, so his mother reopened her family's old glass factory. After his father died, and the factory caught fire, all hope was placed on young Dmitri.

He ended up studying in St. Petersburg, which, thanks to his work, became internationally famous as a center for chemistry research.

Unfortunately, he fell madly in love with a woman who was not his wife. He married her before his divorce from his first wife was final, and was considered a bigamist by the Russian church. This caused him to lose some later opportunities.

He was expected to receive the Nobel Prize for Chemistry in 1906, but some members of the Swedish Academy felt his discovery of the periodic table in the late 1860s had been too long ago, and he lost this opportunity, too.

Dmitri Mendeleev died in 1907 from influenza.


Read more:

Practice: Match the term to its definition below:

  1. benefited (from)
  2. bigamist
  3. divorce
  4. electron
  5. graphic representation
  6. hence
  7. influenza
  8. madly
  9. scheme
  10. textbooks

  1. formal end of a marriage
  2. someone married to more than one person at the same time
  3. books used in school classrooms
  4. in image that helps the viewer understand things
  5. plan; system
  6. part of an atom that goes around the center (or "nucleus")
  7. were helped (by)
  8. deeply, like one who is crazy
  9. a common illness, also called "the flu"
  10. consequently; therefore

Answers are in the first comment below.

Submitted to the Shenzhen Daily for May 25, 2015

1 comment:

  1. Answers to the Practice: 1. g; 2. b; 3. a; 4. f; 5. d; 6. j; 7. i; 8. h; 9. e; 10. c