Science Milestones: Mendeleev & The Periodic Table of Elements

Creating what is arguably the most iconic symbol ever seen in science, Dmitri Mendeleev was passionate about chemistry. He was also an educator and his deepest wish was to find a better way of organizing the subject. Mendeleev’s wish led to his discovery of the periodic law and his creation of the periodic table.

mendeleev

Biography

Dmitri Ivanovich Mendeleev was born February 8, 1834 in Verkhnie Aremzyani, in the Russian province of Siberia. He was the youngest of at least 16 children. He first trained to be a teacher like his father, winning a place at his father’s old college. He continued his studies at St. Petersburg and graduated in 1856 with a master’s degree in chemistry. In 1863 Mendeleev was appointed to a professorship and in 1866 he succeeded to the Chair in the University.

Mendeleev is best known for his work on the periodic table; arranging the 63 known elements into a Periodic Table based on atomic mass, which he published in Principles of Chemistry in 1869. His first Periodic Table was compiled on the basis of arranging the elements in ascending order of atomic weight and grouping them by similarity of properties.  He predicted the existence and properties of new elements and pointed out accepted atomic weights that were in error. His table did not include any of the Noble Gases, however, which had not yet been discovered.

“In a dream I saw a table where all the elements fell into place as required. Awakening, I immediately wrote it down on a piece of paper.”

As new elements that he had predicted were discovered, Mendeleev’s fame and scientific reputation were solidified. In 1905, the British Royal Society gave him its highest honor, the Copley Medal. In the same year he was elected to the Royal Swedish Academy of Sciences. Element 101 is named Mendelevium in his honor. He died two years later of influenza.

mendeleevBring it Home

Science Milestones

To learn more about those born in the month of February, visit the iHomeschool Network’s Birthday Lessons.

 

The Periodic Table of Elements … Up Close & Personal

Periodic Table of the Elements

Photo by E.Lite

When I was in college, I spent a great deal of time on the campus of the University of Oregon.  While I was not a student here, my boyfriend (now my husband) was and I thereby spent a great deal of time with him in Klamath Hall and the Art Library (he liked the intimacy of this library better than the larger Knight Library).  One of the things I remember most about this part of campus was the visual Periodic Table of Elements.  When we had free time in Eugene recently, I knew this was one venue I wanted to share with my kiddos since we had recently spent some time learning a little chemistry ourselves.

I was delighted to discover that the building was accessible in the summer and open to the public.  Prior to our arrival, my kiddos couldn’t quite understand my desire to show them this when I tried explaining it in words.  Once they saw it in person, however, they were excited and very grateful.  They loved finding their favorite elements:  Au, Po, and Ra.  Can you tell we also read a biography of Marie Curie?

I inquired with thestaff as to the specifics regarding the elements on display but to my surprise, no one seemed to know anything.  If memory serves me correct, however, I believe that one mole of each element is on display. A mole is a chemical mass unit, defined to be 6.022 x 1023 molecules, atoms, or some other unit. The mass of a mole is the gram formula mass of a substance. For example, 1 mole of copper has 6.022 x 1023 atoms and weighs about 63.54 grams.