Predict the modes of occurrence of the following three types of metals:
(i) Highly reactive (e.g., Na)
(ii) Moderately reactive (e.g., Fe)
(iii) Noble metal (e.g., Au)

Predict the modes of occurrence of the following three types of metals : (a) Highly reactive (e.g Na ) (b) Moderately reactive (e.g Fe ) ( c) Noble metal (e.g Au ).

Which one of the following will have the largest number of atoms? (i) 1 g Au (s) (ii) 1 g Na (s) (iii) 1 g Li (s) (iv) 1 g of Cl_2 (g)

The main group elements i.e. representative elements complete their electron configuration using s and p electrons in the periodic table. These elements range from the most metallic to the most non-metallic with intermediate properties, the semi-metals, in between .The elements which occur at the two extremes of the periodic table are highly reactive and therefore, these highly reactive elements do not occur in free state : they usually occur in the combined forms. Beryllium and aluminium exhibit many properties which are similar, but, the two elements differ in :

Reactivity of HCHO with the following G.R in the decreasing order is : (i) PhMgBr (ii) PhCH_2 MgBr (iii) (iv) .

Predict the order of reactivity of following compounds in dehydrohalogenation. a. I. II. III. IV. V. b. I. II. III. IV.

Which of the following compounds would undergo Diels-Alder reaction with dienophile (e.g., Maleic anhydride) ?

Reactivity of with the following G.R in the decreasing order is : (i) MeMgBr (ii) EtMgBr (iii) Me_2 CH-MgBr (iv) Me_3 C - MgBr .

Fragmentation, leaching and catabolism are some of the important steps of decomposition. Study the following statements I , ii and iii regarding these and select the correct option. (i) Detritivores (e.g., earthworm) breakdown detritus into smaller particles. (ii) Water soluble inorganic nutrients go down into soil horizon and get precipitated as unavailable salts. (iii) Decomposers (e.g., bacteria and fungi) secrete digestive enzymes and degrade detritus into simpler inorganic substances.

In the following reaction sequence, products (A) to (G) are formed. Product (D) and (E) is:

In the following reactions sequence, the correct structures of E,F and G are