Dmitri Mendeleev

1
Dmitri Mendeleev

• Born February 8, 1834
• The youngest of 14 children
• Had a strong interest in science as a young boy
• Attended college in St. Petersburg
• Had papers published about his original
  experiments by the age of 20.

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• Studied abroad for 2 years with scientist
  Kirchhoff and Bunsen
• His temper caused him to return to Russia
• Wrote a book on organic chemistry since there
  wasnt one available in Russia
• Married at the age of 29 and had 1 daughter and 1
  son, but did not spend much time with them due to
  his tempermental side
• Became a well-loved professor because of his
  enthusiasm

3

• Wrote a 2nd chemistry book (in 60 days) where he
  placed elements with similar properties in groups
  and gave the groups names

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So, how did he come up with the Periodic Table??

• Had been working on organizing the elements for 3
  days straight.
• One morning, while waiting for a train. . .
• Began to jot notes on the back of a letter which
  placed elements in groups in order of atomic
  weight ex) F 19 Cl 35 Br 80
• Then wrote the elements along with their atomic
  weight and properties on individual cards

5

• He couldnt stop, so he missed his train and then
  fell asleep and had a dream where he realized
  that the patterns repeated themselves when the
  elements were placed in order of their atomic
  number
• Mendeleev left gaps where there was no element to
  fit the pattern and predicted the properties of
  these undiscovered elements.

6

• The strongest correlation for this order was the
  number of valence electrons
• Mendeleev called the organization the Periodic
  Law
• It took some time before all people accepted his
  theory, but as more and more elements were
  discovered that matched his predictions, people
  came to agree with the great discovery of
  Mendeleev.