Advertisements
Advertisements
प्रश्न
State the contributions made by Mendeleev towards the periodic table.
उत्तर
Contribution made by Mendeleev:
- Elements were arranged in increasing order of atomic weights in horizontal rows called periods in vertical columns called groups.
- Elements which are similar w.r.t. their chemical properties are grouped together and have atomic weights of nearly the same value.
- Elements in the same group had the same valency and similar chemical properties.
- The properties of undiscovered elements left in the vacant gaps were predicted.
- Incorrect atomic weights of some of the arranged elements were corrected with the knowledge of the atomic weights of the adjacent elements.
- Number of gaps were left in the table for elements not known at that time. Even predicted their properties by studying the properties of neighbouring elements. These elements were later on discovered and their properties were found to be corrected.
APPEARS IN
संबंधित प्रश्न
Helium is an unreactive gas and neon is a gas of extremely low reactivity. What, if anything, do their atoms have in common?
By considering their position in the Periodic Table, which one of the following elements would you expect to have maximum metallic characteristic?
State whether the following statement is true of false:
According to Mendeleev's periodic law, the properties of elements are a periodic function of their atomic numbers.
Which two elements show an ambiguity regarding their sequence in Mendeleev’s periodic table?
Write scientific reason.
There was no definitive place for isotope in Mendeleev’s periodic table.
What are the limitations of Mendeleev's periodic table?
The total number of electrons present in the first twenty elements of the periodic table is ______
In Mendeléev’s Periodic Table the elements were arranged in the increasing order of their atomic masses. However, cobalt with atomic mass of 58.93 amu was placed before nickel having an atomic mass of 58.71 amu. Give reason for the same.
Write the formulae of chlorides of Eka-silicon and Eka-aluminium, the elements predicted by Mendeléev.
Mendeleev's periodic table was based on ______.
