Question

State true or false.
1. Position of isotopes was clearly defined in Mendeleev's periodic table.
2. Position of lanthanides and actinides was clearly defined in Mendeleev's periodic table.

• A. True, True
• B. True, False
• C. False, True
• D. False, False

Answer 1

The correct option is D False, False

Since Mendeleev's classification is based on atomic weights, the position of isotopes was not given. Lanthanides and Actinides were not known at that time. Their position has not been defined in the periodic table.

Hence, both statements are false.