Class 11 Chemistry - Chapter Classification of Elements and Periodicity in Properties NCERT Solutions | The size of isoelectronic species &mdash
The size of isoelectronic species — F–, Ne and Na+ is affected by
(a) Nuclear charge (Z )
(b) Valence principal quantum number (n)
(c) Electron-electron interaction in the outer orbitals
(d) None of the factors because their size is the same.
Isoelectronic species are the species belonging to different atoms or ions which have same number of electrons but different magnitudes of nuclear charges.
The size of an isoelectronic species increases with a decrease in the nuclear charge (Z). For example, the order of the increasing nuclear charge of F-, Ne, and Na+ is as follows:
F- < Ne < Na+
Z 9 10 11
Therefore, the order of the increasing size of F-, Ne and Na+ is as follows:
Na+ < Ne < F-
More Questions From Class 11 Chemistry - Chapter Classification of Elements and Periodicity in Properties
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Write the general outer electronic configuration of s-, p-, d- and f- block elements.
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(a) B > Al > Mg > K
(b) Al > Mg > B > K
(c) Mg > Al > K > B
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(ii) Ar
(iii) Mg2+
(iv) Rb+
- Q:-
Considering the elements B, C, N, F, and Si, the correct order of their non-metallic character is:
(a) B > C > Si > N > F
b) Si > C > B > N > F
(c) F > N > C > B > Si
d) F > N > C > Si > B - Q:-
Assign the position of the element having outer electronic configuration
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- Q:-
How does atomic radius vary in a period and in a group? How do you explain the variation?
- Q:-
Use the periodic table to answer the following questions.
(a) Identify an element with five electrons in the outer subshell.
(b) Identify an element that would tend to lose two electrons.
(c) Identify an element that would tend to gain two electrons.
(d) Identify the group having metal, non-metal, liquid as well as gas at the room temperature. - Q:-
Considering the elements F, Cl, O and N, the correct order of their chemical reactivity in terms of oxidizing property is:
(a) F > Cl > O > N
(b) F > O > Cl > N
(c) Cl > F > O > N
(d) O > F > N > Cl - Q:-
On the basis of quantum numbers, justify that the sixth period of the periodic table should have 32 elements.
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(i) CH2=C=O,
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(iii) (CH3)2CO,
(iv) CH2=CHCN,
(v) C6H6
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Calculate the molecular mass of the following:
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Assign oxidation number to the underlined elements in each of the following species:
(a) NaH2PO4
(b) NaHSO4
(c) H4P2O7
(d) K2MnO4
(e) CaO2
(f) NaBH4
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Explain the formation of a chemical bond.
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(i) used to determine heat changes
(ii) whose value is independent of path
(iii) used to determine pressure volume work
(iv) whose value depends on temperature only. - Q:-
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a) What is the initial effect of the change on vapour pressure?
b) How do rates of evaporation and condensation change initially?
c) What happens when equilibrium is restored finally and what will be the final vapour pressure? - Q:-
Justify the position of hydrogen in the periodic table on the basis of its electronic configuration.
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- Q:-
Consider the reactions:
(a) 6CO2(g) + 6H2O(l) → C6H12O6(aq) + 6O2(g)
(b) O3(g) + H2O2(l) → H2O(l) + 2O2(g)
Why it is more appropriate to write these reactions as:
(a) 6CO2(g) + 12H2O(l) → C6H12O6(aq) + 6H2O(l) + 6O2(g)
(b) O3(g) + H2O2(l) → H2O(l) + O2(g) + O2(g)
Also suggest a technique to investigate the path of the above (a) and (b) redox reactions.
- Q:-
What do you understand by (i) electron-deficient, (ii) electron-precise, and (iii) electron-rich compounds of hydrogen? Provide justification with suitable examples.
- Q:-
Complete the following chemical reactions.
(i) PbS(s) + H2O2(aq) →
(ii) MnO-4(aq) + H2O2(aq) →
(iii) CaO(s) + H2O(g) →
(iv) AlCl3(g) + H2O(I) →
(v) Ca3N2(s) + H2O(I) →
Classify the above into (a) hydrolysis, (b) redox and (c) hydration reactions.
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