 | Democrite, thinker of the Vth century BC, taking back to his master Leucippe talks, suggest an atomic theory: | Matter is made from non-divisible particles ("atomos" in greek). |
 | In the IVth century BC, Empedocle, contrarily to Democrite talks suggest this theory: | Universe is made from four elements :
|
 | At the same periode, Aristote strength the theory by adding four qualitys to the four elements: cold, dry, hot, wet. Those qualitys in couple form elements, who form the universe. This theory reach to explain some freaks of nature. |  |
| 23 century later... | ||
 | In 1808, John Dalton, chemist and physician, rewrite and make deeper atomic theory of democrite: |
|
 | In 1869 Dimitri Ivanovitch Mendeleïev, chemistry professor in St-Petersburg classify elements according to their propertys. Writing a chemistry book, he discover that sorting elements by their atomic mass, a cyclic trend of their propertys appear several times. | |
 First Mendeleïev table | Mendeleïev make his table so that periodicity appear clearly, but to respect his periodicity law in which he trust, he must sometimes modify order and let some cells empty. He was sure that those missing elements will be finally discovered, and so predict the properys of those futur elements (according to the adjacents cells in the table): eka-aluminium, eka-bore and eka-silicium. Between 1875 and 1886, those three elements (gallium, scandium and germanium) where discovered. Each of them had the property predicted by Mendeleïev. | |
Small history of elements classification
3.9/5 based on 47 reviews
Last modified on: August 29th 2023
Other pages you may also like
Bread oven
Building a bread oven was until a few years ago a job for the professionals. But now you can buy a kind of kit which allows you to build your own bred oven without professional masonry know-how. You should know that the kits only provide the main part of oven, the hearth, where you light the fire...1.2M3.6 June 3rd 2024
Random menu...
A complete menu with a starter, main course and dessert, generated at random, to modify as you choose.867K3.9 August 29th 2023
At what time?
This page will automatically calculate for you, in 1 click, the start or end times of a recipe, and answer 2 questions that you may have already asked yourself: - At what time to start this recipe to finish at ...? or else - At what time would I finish this recipe if I start at ...?1.6M 23.9 August 29th 2023
Buy cooking-ez cookbook
Would you like to be able to consult the recipes on this site offline, or print them out? If so, don't hesitate: treat yourself to the cuisine-facile.com recipe book, with the recipes of your choice at a very low price.94K3.6 August 29th 2023
Post a comment or question
Follow this page
If you are interested in this page, you can "follow" it, by entering your email address here. You will then receive a notification immediately each time the page is modified or a new comment is added. Please note that you will need to confirm this following.
Note: We'll never share your e-mail address with anyone else.
Alternatively: you can subscribe to the mailing list of cooling-ez.com , you will receive a e-mail for each new recipe published on the site.