Question

five major differences between Mendeleev periodic table and modern periodic table.

Answer 1

DIFFERENCE:
MENDELEEV periodic table:
                                 Here, hydrogen was not given a specific place.
                                 This periodic table was based on mass number.
                                 It has eight vertical columns called groups and 12 horizondal rows called periods.
                                seperation of metals and non metals cannot be distinguished from each other.
                                 Iso topes are not given place

MORDEN PERODIC TABLE
                
                                  Hydrogen was given a correct place
                                  This periodic table was based on atomic number.
                                  it contain 7 horizontal rows called periods and 18 vertical columns called groups
                                 Separation of metals and non metals can be distinguished from each other.
                                 Iso topes was given its places

Answer 2

Differences between Mendeleev Periodic Table and Modern Periodic Table:

Modern Periodic Table:

• In the modern periodic table all the elements are arranged in the order of increasing atomic number.

• There are 18 vertical columns in the modern periodic table and these 18 columns are called as groups.

• Noble gases like Helium, Neon, Argon etc are placed on the right hand side of the modern periodic table.

• Isotopes are kept in the same place of the modern periodic table because their atomic numbers are same.

• Transition elements are placed in group 3 to group 12. They are placed in the middle of the long period.

Mendeleev's Periodic Table:

• In Mendeleev's periodic table the elements are arranged in the order of increasing atomic mass.

• In Mendeleev's periodic table there are 9 vertical columns known as groups.

• There is no place allotted for noble gases in the modern periodic table.

• He had not given suitable places for isotopes.

• All the transition elements are placed together in group VIII of the Mendeleev's periodic table.