Limitations of Mendeleev's Periodic Table

Q.

In Mendeleevs Periodic Table, why was there no mention of noble gases like Helium, Neon And Argon?

Q.

Which group of elements was missing from Mendeleev's original periodic table ?

Q. Which of the following is not correct about Mendeleev's periodic table?

1. The position of hydrogen in the periodic table was uncertain
2. The isotopes were assigned specific places in the table
3. It helped in correcting the doubtful masses of some elements including beryllium
4. Noble gases once discovered could be placed separately without disturbing the existing order

Q.

The anomalous pairs in Mendeleev’s periodic table is/are _________.

1. Co, Ni

2. Te, I

3. Ar, K

4. All the above

Q. Write a short note on the position of isotopes in the Mendeleev`s and the modern periodic table.

Q.

Choose the incorrect statement in view of Mendeleev's Periodic Table.

1. Isotopes of elements were placed at same position

2. Position of hydrogen was clear

3. Elements were arranged in order of their atomic masses

4. Atomic masses were not strictly followed

Q. Assertion (X): Mendeleev placed Co before Ni in the periodic table by violating the trend of increasing atomic mass

Reason (Y): The sequence was inverted to group the elements with similar properties together

1. Both X and Y are true and Y is the correct explanation of X
2. Both X and Y are true and Y is not the correct explanation of X
3. X is true, Y is false
4. Both X and Y are false

Q.

Which among these are limitations of Mendeleev's periodic table?

1. Position of hydrogen

2. Position of isotopes

3. Similar elements placed separately
   

4. None of These

Q. Assertion :The placement of isotopes in Mendeleev's periodic table overcome in the modern periodic table. Reason: In modern periodic table, the elements have been allotted places based on their atomic numbers

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. Which of the following is not correct about Mendeleev's periodic table?

1. The position of hydrogen in the periodic table was uncertain
2. It helped in correcting the doubtful masses of some elements including beryllium
3. The isotopes were assigned specific places in the table
4. Noble gases once discovered could be placed separately without disturbing the existing order

Q.

Mendeleev's classification was based on _______ .

1. Increasing atomic number

2. Increasing atomic mass

3. Decreasing atomic mass

4. Decreasing atomic number

Q. Nobel gases were included in Mendeleev's periodic table in the:

1. 7th group
2. 1st group
3. 8th group
4. none of these

Q.

The position of Hydrogen could not be justified by Mendeleev.

1. True

2. False

Q.

Isotopes didn't find any place in Mendeleev's periodic table. True or False?

1. True

2. False