Merits and dimerits of Mendeleev's periodic table.
1. He could classify all the 63 elements known at that time on the basis of similarities in properties.
2. He left gaps for the elements yet to be discovered.
3. He predicted the properties of those yet to be discovered elements and thus, helped in the discovery of other elements later on.
4. He named these elements by prefixing a sanskrit numeral 'Eka' (one), 'Divi' (two), 'Tri' (three), etc.to the names of the preceding preceding similar element in the same group. For example : eka - boron, eka - aluminium, eka - silicon, divi - manganese, eka - tantulum, etc.
All these elements were discovered later and did have the properties similar to those predicted by mendeleev. For example -
PROPERTIES EKA - ALUMINIUM GALLIUM
Atomic mass 68 69.7
Formula of oxide E2O3 Ga2O3
Formula of chloride ECL3 GaCl3
1. Although most of the elements were placed in the order of increasing atomic weights but this increasing order could not be maintained in all cases. For example - Cobalt atomic mass is 58.93u preceded Nickel 58.71u preceded Tellurium 127.6 preceded Iodine 126.90, thus he couldnt maintain similarities in properties.
2. Mendeleev periodic table did not provide space for noble gases which were discovered later.
3. Moreover there was no space left for isotopes in medeleev's periodic table.
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mendeleevs attempt was to arrange the elemets in order of atomic masses at rhe same time placing the elements with similar properties in the same groups
meneleevees periodic table didnot give space to noblegases
thanku for the this i got some information adout periodic table
Thankx a lot dhru -thumps up der!!!!!!!