If the three elements X,Y and Z form a triad and atomic weights of X and Z are 9 and 40 respectively then the atomic weight of an element y is _________
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Mass of 10 atoms of an element is `24xx10^(-23)` gm, then atomic mass of that element is:
M ass of `N_(A)` atoms `=(24xx10^(-23))/(10)xx6.022xx10^(23)=14.4 gm` Atomic mass =14.4
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38. Consider three sets \( X, Y \) and \( Z \) having 6,5 and 4 elements respectively. A.11 these 15 elements are distinct. Let \( S=(X-Y) \cup Z \). How many proper subsets does \( S \) have? (a) 255 (b) 256 (c) 1023 (d) 1024
Given : n(X)=6 n(y)=5 n(z)=4 Also,the elements are distinct Therefore,these three are disjoint sets ==>n(X∩Z) =0 -------- (1) Now,her S=(X-Y)∪Z=X∪Z [Because X∩Z=∅==>X-Z=X] ==>n(S)=n(X∪Z) ==>n(S)=n(X)+n(Z)-n(X∩Z) ==>n(S)=n(X)+n(Z)-0 [From (1)] ==>n(S)=6+4=10 Therefore, Number of proper subsets of S=2n(S)-1 ...
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A mixture of CuS (molecular weight = `M_(1)`) and `Cu_(2)S` (molecular weight `=M_(2)`) is oxidised by `KMnO_(4)` (molecular weight `=M_(3)`) in acidi
Correct Answer - `(M_(1))/(6), (M_(2))/(8), (M_(3))/(5)`
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In the periodic table, vertical columns of elements are called _______ and horizontal rows of elements are called _______.
Correct Answer - groups, periods
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Fill in the Blanks The choice of Bt genes depends upon _______(a)_______and _______(b)_____as most Bt toxins are ____(c)_______
Correct Answer - (a) The crop (b) the target pest (c) Insect group specific
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Three numbers form a GP. If the third term is decreased by 128 then, the three numbers, thus obtained, will form an AP. If the second term of this AP
Correct Answer - `(8)/(9), (104)/(9) and (1352)/(9)`
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Atomic weight = ……………….. x equivalent weight
Correct option is C) valency
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The atomic weight of a bivalent element is 9. The equivalent weight of same element is
Correct option is C) 4.5
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The set of elements that is not Dobereiner triad from the following
Correct option is D) S, Si, Te
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If an element X belongs to II group and another element Y belongs to VII group then the compound formed between these elements has fomula :
Correct option is C) X Y2
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