Three elements X, Y and Z belong to 17th group but 2nd, 3rd and 4th period respectively. Number of valence electrons in Y is 7. Find the number of valence electrons in X and Z.
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The elements Li(Z = 3), Na (Z = 11) and K (Z = 19) belong to group 1. (i) Predict the periods they belong.
(i) The Period number to which these elements belong are Li=2nd Period Na =3rd Period K= 4th Period (ii) In a Group the chemical reactivity of metals from top to bottom increases. Lithium is least reactive. (iii)...
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Na, Mg, Al and P belong to 3rd period but are placed in first, second, thirteenth and fifteenth group.
It is three in Na, Al and P. Elements with the same number of occupied shells are placed in the same period
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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 'A' and 'B' belong to the 3rd period of Modern periodic table and are in group 2 and 13 respectively.
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Na, Mg and Al are the elements of the same period of modern periodic table having one, two and three valence electrons respectively.
(i) Na/Sodium. Reason: The atomic size decreases from left to right due to the increase in the nuclear charge. (ii) AI/Aluminium. Reason: The tendency to Iose electrons decreases from left to right. Detailed Answer: (i) Na...
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Two elements 'P' and 'Q' belong to the same period of the modern periodic table and are in Group -1 and Group -2 respectively.
Sr. No. Property P o (i) No. of electrons in the atom 3 11 19 4 12 20 (any one pair) (ii) Size of the atom Bigger Smaller (iii) Metallic character More metallic Less metallic (iv) Tendency to lose electrons More More (v) Formula of oxides P2O QO (vi) Formula of chlorides PCI QCl2 Note: For parts (v) and (vi) examples using symbols of elements may also be accepted. Detailed Answer: (i) P...
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The elements ,4Be, 12Mg and 20Ca each having two valence electrons in their valence shells are in periods 2,3 and 4 respectively
(i) They all belong to group 2 because of all three have 2 electrons in their outermost shelll. (ii) Be is least reactive because it has 2 shells and due to,...
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Four elements P, Q, R and S belong to the third period of the Modern Periodic Table and have respectively 1,3, 5 and 7 electrons
Electronic configuration of Q = 2, 8,3 Valency of Q =3 Electronic Configuration of R = 2,8, 5 Valencyof R=8-5=3 Electronic configuration of P = 2,8,1 Electronic configuration of S=2,8,7 Formula : PS/NaCl
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The elements Li, Na and K each having one valence electron, are in period 2, 3 and 4 respectively of modern periodic table.
(i)They are in group 1 because all the elements in a group have 1 valence electron. They form positively charged ions by losing one electron. (ii) Lithium is least reactive because the reactivity...
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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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