Mendeleev predicted the existence of certain elements not known at that time and named two 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) Why is such a classification of elements compared with a characteristic of musical scale ?


(d) State one limitation of this classification of elements.

(a) (i) Gallium is the new element which has taken the place of eka – aluminium.

(ii) Germanium is the new element which has taken the place of eka silicon.


(b) These elements are placed in the 4th period of the modern periodic table.


(c) As we know that in musical scale the eight notes are repeating so Newland compared it with the musical scale because in his law the property of the 1st element is same as the 8th.


(d) This classification of the element was only applicable to the Calcium.


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