Question

write any two drawbacks of Mendeleev's periodic table
write the advantages of Mendeleev's periodic table.
Why did Mendeleev lave gaps in his periodic table?
State modern periodic law.
10 What are the merits of modern periodic table?
11Give reasons for placing hydrogen along with alkali metals (IA
12. Write any three differences between groups and periods.
13. What does e-block elements mean?
14. Why are the elements of group 18 called zero valent?
15 Why argon is called inert gas?​

Answer 1

• position of hydrogen -hydrogen is placed in group 1of the periodic table . however it resembles the element of both group 1 and group 7. therefore the position of hydrogen wasn't clear.
• metals and nonmetals-attempt has been made to place metals and nonmetals separately in Bangalore periodic table.

advantages of Mendeleev periodic table

• grouping of elements. hi general is the study of the elements then known to study of mere 8 groups .
• prediction of properties of undiscovered elements.he protect the properties of then unknown elements on the basis of properties of elements lying at the centre the vacant slots.

mendeleeve left gaps in product table in order to maintain the trend Mendeleev left gaps in his product table to keep the elements with similar properties together. he predicted that elements would be discovered later and they would occupy those gaps.

the modern periodic law states that physical and chemical properties of the elements isthe periodic function of the atomic numbers.

• this classification is based on the atomic number which is a more fundamental property of the elements.