Friends,
I understand that you have your doubts about my dear friend Dmitri Mendeleev. You might be convinced that every word of his discoveries are wrong. I have a lot of evidence against you. But before you completely disregard my letter, I have something to tell you. My dear friend Dmitri Mendeleev has made a great scientific achievement. You may be against the fact that he has succeeded. I have evidence against you. Please finish reading this letter before you either rip it up or throw it in the fire.
Dmitri Ivanovich Mendeleev was born February 8, 1834. He was the youngest child out of perhaps a dozen. When he was young, his father went blind. His mother worked at the glass factory as the manager. Alas, my friends, the factory exists no more, but his mother was determined to give young Dmitri an education, even without a job. Exactly ten days after he was enrolled in a local school, she died of tuberculosis. The dreaded disease removed his father and another of his siblings as well. But Dmitri was determined to study science and make an achievement, even in the midst of sorrow and sadness.
Dmitri Mendeleev organized and explained the elements on what is now known as the periodic table, some of which demonstrated a natural order. Dmitri wrote what he knew on cards. He drew the element, the symbol, the mass, and the atomic number. He did this with the 63 known elements at that time. He brought these cards everywhere he went. One day, Mendeleev went to catch a train. As he waited for the train to come, he arranged and re-arranged the cards. He was so caught up in this that he missed the train completely. He stayed doing this for about three days, until he noticed a pattern. Some say that after these three days, Dmitri fell asleep. Later he says that in his dreams, he saw a table with the elements simply falling into place. When he awoke he wrote it down immediately. It was a table, the Periodic table, and the elements were placed in the order of increasing atomic number, the number of protons in the element. There were blank places in the table, and many scorned Mendeleev for leaving it that way, (like you) but Dmitri just predicted not only that there would someday be more elements in the table, but he predicted their reaction, weights and densities.
There was a rough time in Mendeleev’s life where nobody believed him. But a few years later, a French scientist discovered the element Gallium, and it fitted into Mendeleev’s table perfectly and just as he had predicted. A few years later, the element Germanium was discovered and slid into place perfectly. After this, scientists began to look for new elements to fit in. Mendeleev, having died February 2, 1907, did not see all of them placed in, but only a few, which was good enough for him. Soon people began to slightly believe Mendeleev and what he said. Once the elements practically stepped right where they belonged, he began to be believed.
If you were to look at a periodic table, you would see rows and columns. Since you are scientific experts, you know that each of the columns is called a family. They all have similar properties and the same amount of electrons in the outer shell. But they all have different numbers of energy rings in them. The atoms that make up Row 1’s elements all have 1 energy shield. Second row has two, third row has three, and so on and so forth. If you look at the squares, you see numbers. They mean the atomic number. Hydrogen is one, Helium two, Lithium three, etcetera. But they are placed in the rows because of increasing atomic number, but in a way so that they have similar properties and are grouped with elements “of their kind”.
Of the properties, they would be something like this:
- Are the elements reactant?
- Are they metal, nonmetal, or gas?
- What color are they?
- Do they conduct electricity? How about heat?
- Weight similarities. Do they weight similarly, or are they unique?
Things like that. All atoms have an atomic mass. They aren’t the same, since each element is different, but they can be similar. The size of the atom matters. Each proton, neutron and electron makes the atom a little bit bigger. Each element has a different atomic mass, so it has a different size that other atoms. Every element has a different amount of protons, neutrons, and electrons, so that makes them heavier or lighter than others.
Dmitri had some information that other scientists had already discovered. But this is not bad or wrong. Simple elements, like gold, silver, copper, lead, tin, and mercury have been used since the time of the Ancient Greeks, and Dmitri used some other work from his fellow scientists. A German scientist named Hennig Brand discovered Phosphorus, and another German scientist named Johann Pöbereiner grouped some elements by their similarities. A man named Jhon Newlands sorted the 63 known elements by atomic mass. Lothar Meyer even tried to make a table like Mendeleev’s, but Mendeleev’s table was published about a year before Meyer’s, so naturally, he got the credit.
There were other tables drawn before Mendeleev’s, but Dmitri’s was easiest to read and the best one with the best and most information. He had drawn it out with natural patterns to make everything in his table much easier to both read and understand. He basically put in an instruction manual for us to use. In 1789, a French scientist bearing the name Antoine Lavoisier defined what was meant by a chemical element and drew a table that contained the 33 known elements at that time. He grouped them into gases, nonmetals, metals, and earths. Dmitri built on from there. As there became more and more elements, scientists began to understand some patterns that were in there better and better. In 1862, a French geologist Alexandre Beguyer de Chancourtois published a list of all the known elements. He drew on a helical graph wrapped around a cylinder. But since he used geological terms and used ions and compounds, his work was completely ignored until Mendeleev. And, as I am sure, nobody could read the work on his graph because it was wrapped around a cylinder.
So, my friends, I hope for my dear friend’s sake that you believe me. I have listed the sources used to come up with all of this evidence. Please look carefully upon it and make sure you understand what I have told you. Please note that this letter was carefully researched and written in such a way that you either believe me and stop shutting my friend down, or you refuse to stop and remember my words forever. So please rethink your ways, explore my sources, and think over what I have said. I hope to see you soon, and top of the morning to you.
Your Witness,
Liliana Echeverria
https://docs.google.com/document/d/1W65TS4N0AmYBDrcCj_PbXPF---2XyfxZ_RzMAijLH9c/edit
https://drive.google.com/file/d/0B3WRSr_TQ5mkR0I2d1ZhTWZzLXc/view
https://prezi.com/i0pp_l24wy8p/the-discovery-of-the-periodic-table/ utm_campaign=share&utm_medium=copy
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