merits and d merits of nendelvess periodic table
Answers
Answer:
Merits of Mendeleev Periodic Table. Some gaps were left for the elements yet to be discovered. Thus, if a certain new element is discovered, it can be placed in a new group without disturbing any existing group.
The demerits of the periodic table given by Mendeleev are :
He could not place the element Hydrogen in appropriate position in the periodic tabular form.
There was no regular trend in increasing of atomic mass when moved along the elements.
More elements was yet to be known.
hope this help you.
mark as best as your wish
Answer: #BAL #ANSWERWITHQUALITY
MERITS :
1. To give proper place in the periodic table atomic masses of some element where revised in accordance with their properties.
2. Mendeleev kept some vacant places in the periodic table for elements that were yet to be discovered.
3. Mendeleev created zero group without disturbing the original periodic table in which noble gas is fitted very well.
DEMERITS :
1. There was an ambiguity regarding sequence of Cobalt and Nickel in Mendeleev's periodic table.
2. Isotopes were discovered long after Mendeleev put forth periodic table . Challenges posed in placing isotopes in Mendeleev's periodic table as isotopes have same chemical properties but different atomic masses.
3. Rise in atomic mass does not appear to be uniform when elements are arranged in increasing order of atomic masses. It was not possible to predict how many elements could be discovered between two heavy elements.
4. Hydrogen shows similarity with Halogen (group 7). In the same way there is similarities in chemical property of hydrogen and alkali metal. Thus it was difficult to decide correct position of hydrogen whether it is in group of alkali metals are in group of halogens.