Achievements of Mendeleev's Periodic Table

Q.

State the merits of Mendeleev's classification of elements.

Q.

Which eka aluminium element was predicted by Mendeleev?

Q.

Why did Mendeleev leave some gaps in his periodic table of elements ? Explain your answer with an example.

Q. State true or false.
Gallium and germanium (discovered later) are placed below aluminium and silicon in their respective groups. The names of Gallium and Germanium as given by Mendeleev are Eka-aluminium and Eka-silicon.

1. False
2. True

Q.

Gallium and germanium (discovered later) are placed below aluminium and silicon in their respective groups. The names of Gallium and Germanium as given by Mendeleev are Eka-aluminium and Eka-silicon.

1. True

2. False

Q.

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

(a) Name the elements which have taken the place of these elements.

(b) Mention the group and the period of these elements in the Modern Periodic Table.

(c) Classify these elements as metals, nonmetals or metalloids.

Q. Gallium and germanium (discovered later) are placed below aluminium and silicon in their respective groups. The names of Gallium and Germanium as given by Mendeleev are Eka-aluminium and Eka-silicon.

1. False
2. True

Q.

What was the name given to Eka-silicon after it was discovered?

1. Germanium

2. Magnesium

3. Gallium

4. Scandium

Q.

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

(a) Name the elements which have taken the place of these elements.

(b) Mention the group and the period of these elements in the Modern Periodic Table.

(c) Classify these elements as metals, nonmetals or metalloids.

Q.

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

(a) Name the elements which have taken the place of these elements.

(b) Mention the group and the period of these elements in the Modern Periodic Table.

(c) Classify these elements as metals, nonmetals or metalloids.

Q. Mendeleev predicted the existence of some elements that had not been discovered at that time and left some gaps in his periodic table. What are the names that he gave to the two undiscovered elements, gallium and germanium, respectively?

1. Eka-aluminium and Eka-silicon
2. Eka-aluminium and Eka-boron
3. Eka-boron and Eka-aluminium
4. Eka-silicon and Eka-aluminium

Q. What were the names used to denote the existance of undiscovered elements such as gallium and germanium respectively?

1. Eka-aluminium and Eka-silicon
2. Eka-boron and Eka-aluminium
3. Eka-silicon and Eka-aluminium
4. Eka-aluminium and Eka-boron