Question

Answer the following questions:- 1. Name four defects of Mendeleev's periodic table. 2.State modern periodic law.3.What are normal elements?
4.What is the cause of periodicity?
5.What are the merits of the long form of the periodic table?
6.What are the two major defects of long form of the periodic table?
Note:- Don't tell irrelevant answers. If you give me the right answers of all questions then I give you 50 points. ​

Answer 1

Answer:

1-Defects of mendeleev's periodic table:

1. position of hydrogen
2. anomalous pairs of elements
3. position of isotopes
4. position of lanthanides and actinides
5. grouping of elements
6. cause of periodicity.

2 - the modern periodic table is also known as the long form of the periodic table.The classification is based on the principle that " the physical and chemical properties of the elements are the periodic function of their atomic numbers". In the modern periodic table elements are arranged in increasing order of their atomic numbers.

3 - there are 92 normal and remaining are synthetic elements in 118 elements so far.

4-periodicity is the recurrence of characteristic properties of elements arranged in the table, at regular intervals of period.

5- the long periodic table is arranged as in increasing order of their atomic numbers.so , because of this it is easier to identify the elements . according to their atomic masses the elements are arranged based on their atomic masses. the elements are in successive serial order.

6 - position of hydrogen: hydrogen is shown as metals and non metals but it is kept in alkali metals.

position of helium: it is kept with the along of p block elements.

position of lanthanides and actinides:the not placed in the main body of the periodic table.

nt sure about 3rd answer