Two elements A (atm. wt. 75) and B (atm wt. 16) combine to yield a compound. The percentage by weight of A in the compound was found to be 75.08. The formula of the compound is -
(A) AB
(B) AB2
(C) A2B
(C) A2B3
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If S and T are two sets such that S has 21 elements, T has 32 elements, and S ∩ T has 11 elements, how many elements does S ∪ T have
It is given that: n(S) = 21, n(T) = 32, n(S ∩ T) = 11 We know that: n (S ∪ T) = n (S) + n (T) – n (S...
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If X and Y are two sets such that X has 40 elements, X ∪Y has 60 elements and X ∩Y has 10 elements, how many elements does Y have
It is given that: n(X) = 40, n(X ∪ Y) = 60, n(X ∩ Y) = 10 We know that: n(X ∪ Y) = n(X) + n(Y) – n(X ∩ Y) ∴ 60 = 40...
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Two lithium nuclei in a lithium vapour at room temperature do not combine to form a carbon nucleus because
(d) Coulomb repulsion does not allow the nuclei to come very close.
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Which of the following statement about a compound is incorrect? (I) A molecule of a compound has atom of different elements.
(III) because a compound doesn’t retain the physical properties of its constituents.
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One of the statements of Dalton’s atomic theory is given below: “Compounds are formed when atoms of different elements combine in a fixed ratio”
(i), (iv). Statements (i) and (iv) involve masses and volume, respectively. Therefore, these are not related to the statements.
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When two or more atoms are combine in definite ratio is called: (A ) Mixture
(C) compound
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Why phosphorous is not found in atmosphere? 1. It doesn’t combine well with other elements
(d) Phosphorous is not found in atmosphere because at normal temperature and pressure phosphorous is at a liquid state.
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The atomic numbers of three elements X, Y and Z are 3,11 and 17, respectively' State giving reason which two elements will show
The two elements X and Y will show same chemical properties because they have same number of valence electrons in group. They form positively charged ions by losing one electron
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Two elements X and Y have atomic numbers 12 and 16 respectively. To which period of the modern periodic table do these two elements belong ?
Electronic configuration of element X, atomic number 12=2;8;2 Electronic configuration of element 'Y' atomic number 16=2,8,6 Both have three shells, so they belong to period 3. They will form an ionic bond as x...
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Two elements X and Y belong to group 1 and 2 respectively in the same period of the periodic table. Compare these elements with respect to :
(i) Number of electrons in the outermost orbit of X=1 and Y=2. (ii) Valency of X=1 and Y=2. (iii) Metal X is more metallic than Y. (iv) Atomic size of X is bigger than...
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