Question

Which of the following is incorrect statement about Mendeleev's classification of elements?

• A. He could classify all the elements including noble gases.
• B. He left gaps for some yet to be discovered elements.
• C. He predicted the properties of some undiscovered elements.
• D. There was no place for isotopes in his table.

Answer 1

Answer: (A)

He could classify all the elements including noble gases.

Mendeleev periodic table is based on atomic weights of elements,

$(\ast )$ He left no place for isotopes in his table.

$(\ast )$ Predicted the properties and left gaps for discovered elements.

$(\ast )$ He could not classify all elements including noble gases.

Ans :- A.