If packing fraction of two dimension unit cell shown in figure is A, then calculate value of 1000 A.

[Tale `pi = 3.2, sqrt(2) = 1.4]` Fill your answer as sum of digits (excluding decimal places) till you get the single digit answer.

Consider the following elements B C F Cl N O If x,y and z are the number of elements having more electron affinity (Ea_(1)) than nitrogen, the number of elements having ionisation energy more than that of Na and the number of elements having electronegativity more than (or) almost equal to N respectively, find x+y+z . Fill your answer as sum of digit (excluding decimal places) till you get the single digit answer.

Calculate % mass loss when MgCO_(3)(s) is thermally decomposed to MgO(s) "and" CO_(2)(g). [Give answer excluding decimal places]