Mendeleev predicted the existence of certain elements not known at that time and named two of them as eka-aluminium and eka-silicon. Swati has been given an assignment in the class on Mendeleev's periodic table. She has to answer the following questions in the assignment:

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

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

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

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

(v) How has the classification of elements according to modern periodic table helped in making the study of chemistry easy?

Asked by Topperlearning User | 13th Jul, 2015, 03:02: PM

Expert Answer:

(i) (a) Gallium (b) Germanium.

(ii) 4th period.

(iii) Gallium: 13th group; Germanium: 14th group.

(iv) Gallium: Metal; Germanium: Metalloid.

(v) In the periodic table, all the elements have been divided into a few groups of elements. It is much more convenient to study the properties of a few elements of each group than to study the properties of all the elements separately.

Answered by  | 13th Jul, 2015, 05:02: PM