In the given elements how many cannot form amalgam with Mercury?
A) Na
B) Fe
C)Zn
D) K

In the given reaction how many of the following products (1-9) can be formed.

Among the following elements how many of them are inner transition elements ? (a) Sg , (b) Bk , (c ) Er , (d) Fm (e) Fe , (f) Pb , (g) Cr , (h) Ca (i) Ar , (j) Zr , (k) Ce

Amongest the following elements, how many occurs in the earth's crust in the native state ? Au,Pt,Hg,Zn,Fe .

How many of the following elements show +2 as their most stable oxidation state ? Sc, Sn, Zn, Be, Pb, Co, Ag, Ti, Fe

Which of the given statements for mercury cell are incorrect? (i)Mercury cell is suitable for low current devices like hearing aids, watches, etc. (ii)It consists of zinc-mercury amalgam as anode and a paste of HgO and carbon as the cathode. (iii)The electrolyte is a paste of Zn(OH)_2 and KO_2 . (iv)The electrolyte reactions for the cell are At anode : Zn(Hg)+ H_2O to ZnO_((s)) + 2OH^(-) + 2e^(-) At cathode : HgO + H_2O + 2e^(-) to Hg_((l)) + 2OH^-

During spermatogenesis how many spermatozoa are formed from a single primary spermatocyte? (a) 1 (b) 2 (c) 4 (d) 8

Set A has m distinct elements and set B has n distinct elements. Then how many different mappings from set A to set B can be formed?

Among K,Ca,Fe and Zn the element which can form more than one binary compound with chlorine is

Indicate wheter the following pairs of elements form ionic or covalent compounds Also write their molecular formula (a) C and S (b) Na and CI (c ) S and O (d) Ca and H .

How many of the following are water soluble vitamins ? A, B, C, D , K, E