Question

3. What are the limitations of Mendeleev's
periodic table?

4. State any five features of modern periodic table​

Answer 1

Limitation of mendeleev's preodic table:

1. he used Atomic mass so isotopes can't be placed in the table as they have same Atomic number but different mass

2. he placed some elements on the wrong place

answer 4: features modern preodic table :

1. Elements are arranged in the increasing order of atomic numbers.

2. Elements in the modern periodic table are arranged in 7 periods and 18 groups.

3. Horizontal rows are called periods and vertical columns are called groups.

4. Elements are placed in periods based on the number of shells in their atoms

5. Isotopes find place in this preodic table