Achievements of Mendeleev's Periodic Table

Q.

What are the merits of Mendeleevs periodic table?

Q. Which were the elements predicted by Mendeleev in his periodic table?

1. eka-aluminium ($E_a$ )
2. eka-boron ($E_b$ )
3. eka-carbon ($E_c$ )
4. eka-manganese ( $E_m$)

Q.

What are Anomalous pairs of elements?

Q.

(a) How do the properties of eka-aluminium element predicted by Mendeleev compare with the actual properties of gallium element? Explain your answer.

(b) What names were given by Mendeleev to the then undiscovered elements (i) scandium (ii) gallium, and (iii) germanium?

Q.

Mendeleev predicted the existence of certain elements not known at that time and named two of them as eka-aluminium, and eka-silicon.

(a) Name the element which has taken the place of (i) eka-aluminium and (ii) eka-silicon

(b) Mention the period/periods of these elements in the modern periodic table.

(c) Write the group/groups of these elements in the modern periodic table.

(d) Classify these elements as metals, non-metals or metalloids.

(e) How many valence electrons are present in the atoms of each of these elements?

Q.

The correct formula of the oxide of Eka-aluminium element predicted by Mendeleev was :

(a) $Ea{O}_3$ (b) $E{a}_3{O}_2$ (c) $E{a}_2{O}_3$ (d) $EaO$

Q.

Name two elements whose properties were predicted on the basis of their positions in Mendeleev’s periodic table.

Q.

(a) In Mendeleev’s periodic table, a gap was not left for one of the following elements. This element is :

(a) gallium (b) beryllium (c) germanium (d) scandium

Q.

What do you mean by eka - aluminum?

Q. limitations of mendeleev periodic tabl

Q.

Modern periodic table also known as long form of periodic table has the atomic number of elements as the basis of classification .It is better than Mendeleevs periodic table in many respects because it had regarded atomic masses of element as the basis of classification which is not correct .Actually mass of an element is concentrated mainly in the nucleus of the atom and has very little to do with the properties in particular .Electrons involved in these and are linked with atomic numbers of the element.

Which group of elements represent halogen family?

Q. Question 47(a)
Mendeleev predicted the existence of certain elements not known at that time and named two of them as Eka-Silicon and Eka-Aluminium.

Name the elements which have taken the place of these elements.

Q. Which of the following element had a controversial placement in modern periodic table?

1. Helium
2. Silicon
3. Hydrogen
4. Carbon

Q.

In the modified Mendeleev’s periodic table, ________ groups and ________ periods are present, whereas in modern periodic table, _____ groups and _____ periods are present.

Q.

Which chemical compounds of elements were used by Mendeleev to gauge their chemical similarities?

1. A, C

2. A, B, C

3. B, D

4. A, B, C, D

Q. How many elements are discovered till now?

1. 114
2. 96
3. 102
4. 118

Q.

(a) State the merits of Mendeleev’s classification of elements

(b) Describe two anomalies of Mendeleev’s periodic classification of elements.

Q. How many elements are discovered till now?

1. 114
2. 96
3. 102
4. 118

Q. How did Mendeleev predict the existence of some elements yet to be discovered elements in his periodic table?

1. Gaps
2. Atomic number
3. Mass number
4. None of the above

Q. Which of the following element(s) was/were not known when Mendeleev gave his classification?

1. Germanium
2. Gallium
3. Scandium
4. All of the above

Q. Eka-aluminium forms chloride of the type :

1. $E_{2}Cl$
2. $EC{l}_3$
3. $E_{2}C{l}_3$
4. $E_{3}C{l}_4$

Q. Statement 1: Mendeleev left some gaps in his periodic table for the elements not discovered back then.​
​
Statement 2: The position of hydrogen was specified in the Mendeleev’s periodic table.​

1. Both statements are correct. ​
2. Only statement 2 is correct.​
3. Both statements are incorrect.​
4. Only statement 1 is correct.​

Q. Which of the following statements are correct about Mendeleev's periodic table?
i) It is based on increasing order of atomic numbers.
ii) Mendeleev corrected the atomic weight of some elements like Be, In etc.
iii) $(Ar,H_2),(Co,C{l}_2),(Te,F_2)$ are three inverted pairs.
iv) It is based on increasing order of atomic weights.

1. only (iii) correct
2. only (i) correct
3. (ii) and (iv) are correct
4. (i) and (iv) are correct

Q. In the periodic table as formulated by Mendeleev, which of the following constitute an anomalous pair of elements?

1. $Br$ and $Ne$
2. $H$ and $He$
3. $K$ and $Ar$
4. $Na$ and $B$

Q. Elements are classified on the basis of similarities in their properties.

1. True
2. False

Q. Atomic weight of which set of elements were corrected by Mendeleev?

1. $Li,Na,K$
2. $U,Be,In$
3. $Tc,Sc,Al$
4. None of the these

Q.

In Mendeleev’s periodic table, gaps were left for the elements to be discovered later on. An element which found a vacant place in the periodic table later on is :

(a) Be (b) Si (c) Ge (d) Se

Q. Mendeleev used a Sanskrit numeral before the names of the predicted elements. What was the term used for it?

1. Sasi
2. Eka
3. Astan
4. Pancan

Q. What type of oxide would Eka-aluminium form?

1. $E_3{O}_2$
2. $E{O}_3$
3. $E_2{O}_3$
4. $EO$

Q. Mendeleev corrected the atomic weight of:

1. $Be$
2. $In$
3. $Os$
4. all of the above