What was the main drawback of Mendeleev's periodic table?Many elements have several isotopes.Noble gases do not form compounds.Some groups stand divided into two sub groups A and B.Atomic weights of elements are not always whole numbers.
Question
What was the main drawback of Mendeleev's periodic table?Many elements have several isotopes.Noble gases do not form compounds.Some groups stand divided into two sub groups A and B.Atomic weights of elements are not always whole numbers.
Solution
The main drawback of Mendeleev's periodic table was that it was unable to accurately predict the properties of certain elements and their compounds. This was due to several reasons:
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Many elements have several isotopes: Mendeleev's table was based on atomic weights, not atomic numbers. This caused problems because many elements have isotopes with different atomic weights. This means that the same element could appear in different places on the table, depending on which isotope was being considered.
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Noble gases do not form compounds: When Mendeleev created his table, the noble gases (Group 18) had not yet been discovered. When they were, it was found that they did not fit into his table because they do not readily form compounds with other elements.
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Some groups stand divided into two sub groups A and B: Mendeleev's table divided some groups into two subgroups, A and B. This was confusing and did not accurately reflect the properties of the elements in these groups.
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Atomic weights of elements are not always whole numbers: Mendeleev's table was based on atomic weights, which are not always whole numbers. This caused problems with the placement of some elements on the table. For example, the element iodine has an atomic weight of 126.90447, but it was placed before tellurium, which has an atomic weight of 127.60, because Mendeleev predicted that the order would be reversed based on their properties.
Similar Questions
ue with Mendeleev's 1871 Periodic Table:First Issue:Noble gases were not included because they hadn't been discovered yet.Second Issue:Pairs of elements (e.g., Co and Ni) didn't fit into groups as expected based on their properties when arranged by atomic masses.Reason for Discrepancy:Later discovery of isotopes, different forms of an element with varying neutron numbers.Understanding Isotopes:Atomic mass of an element is an average of its isotopes' masses, considering their relative abundances.Impact on Mendeleev's Arrangement:
Why did Mendeleev leave gaps in his version of the periodic table?
Explain why Mendeleev modified earlier versions of the periodic table.
What breakthrough did Mendeleev make in devising a periodic table that was accepted by the scientific community?He arranged the elements in order of atomic weightHe left gaps in the table for unknown elementsHe devised the ‘law of octaves’He published the first full list of all the elements2Which of the following statements about the modern periodic table is not true?The number of shells decreases down a groupElements in the same group have the same number of electrons in the outer shellElements are arranged in atomic number orderElements in the same period have the same number of shells3Where are the non-metal elements found in the periodic table?On the rightAt the topAt the bottomOn the left4Which of the following elements, shown by its electronic structure, is found in group 2 of the periodic table?2, 8, 22, 72, 8, 12, 8, 45Why do fluorine, chlorine and iodine all have similar chemical properties?They are all metalsThey all have 7 electrons in their outer shellThey are all in the same periodThey all have odd numbers of electrons
How is the modern periodic table different from Dmitri Mendeleev's table?A.Elements are now organized by increasing atomic mass.B.The lanthanides and actinides are now in rows below the main table.C.Elements that have similar properties are now grouped together.D.The table is now used to predict the properties of elements.
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