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Dmitri Mendeleev's Table

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The earliest recorded attempts to make sense of the few known elements were conducted by a German scientist, Dobereiner , who came to realise that elements reacted similarly to those of alike atomic weights. This discovery lead to the masses of scientists trying to find a pattern within the reactions and properties in order to efficiently find an order to put the elements in. The periodic table was previously known as Mendeleev's table. It was named after the scientist Dmitri Mendeleev, of whom came up with the original idea of putting the sixty three known elements in the 1860s into a table. While organising it in order of ascending atomic masses (weights as they were known as at the time) Mendeleev left gaps in order to compensate for the …show more content…

As well as this, their position on the periodic table makes them alkali metals, which means that they all have low boiling and melting points. As well as this, they will react violently when placed in water and will create a strong base and hydrogen gas as the products of the reaction. Group seven elements are known as halogens and consist of five non-metal elements with seven electrons in their outer shell. Much like the elements in group one, halogens are also only one electron away from being stable. Group seven elements are found in all three states of matter at room temperature with iodine and astatine found in solid form, bromine in liquid and chlorine and fluoride in gas.
Group eight elements are also known as group zero due to their low reactivity. Their inability to react with other elements stems from the fact they all have complete outer shells, meaning they don't not need to either gain or lose any electrons to reach a stable state. Additionally, they were some of the last mass discoveries concerning the periodic table. Despite the noble gases stablility, some can still from compounds with oxygen and fluorine (krypton and xenon are examples.) due to the fact all of the electrons in their shells are partnered, they have very low melting and boiling points with, helium's melting point being " -272'C " . Additionally, if the atomic masses of these elements were to increase, so would their boiling and melting points along with their

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