Q.1 The order of screening effect of electrons of s, p, d and f orbitals of a given shell of an atom on its outer shell electron is: Option 1 s> p > d > f Option 2 f> d > p > s Option 3 p> d > s > f Option 4 f> p > s > d Correct Answer 1 Explanation s has greatest effect to reduce the force of attraction between the outermost electron and nucleus due to its effective charge density followed by p> d > f .

Passage Text Nuclear charge actually experienced by an electron is termed as . The effective nuclear charge Z* actually depends on type of shell and orbital in which electron is actually present. The relative extent to which the various orbitals penetrate the electron clouds of other orbitals is. s> p > d > f (for the same value of n) The phenomenon in which penultimate shell electrons act as screen or shield in between nucleus and valence shell electrons and thereby reducing nuclear charge is known as shielding effect. The penultimate shell electrons repel the valence shell electron to keep them loosely held with nucleus. It is thus evident the more is the shielding effect, lesser is the effective nuclear charge and lesser is the . Q.2 Which of the following experience maximum effective nuclear charge? Option 1 4s 1 Option 2 4p 1 Option 3 3d 1 Option 4 2p 3 Correct Answer 4 Explanation Effective nuclear charge depends on type of shell and orbital. 2p 3 is the closest to the nucleus

Q.3 Which of the following is not concerned to effective nuclear charge? Option 1 Higher ionization potential of carbon than boron Option 2 Higher ionization potential of magnesium than aluminium Option 3 Higher values of successive ionization energy Option 4 Higher of higher oxidation state Correct Answer 2 Explanation Conceptual

Q.4 Ionization energy is not influenced by : Option 1 Size of atom Option 2 Effective nuclear charge Option 3 Electrons present in inner shell Option 4 Change in entropy Correct Answer 4 Explanation Conceptual

Q.5 The electronic configuration of gadolinium ( 64) is Option 1 [Xe] 4f 3 5d 5 6s 2 Option 2 [Xe] 4f 7 5d 2 6s 1 Option 3 [Xe] 4f 7 5d 1 6s 2 Option 4 [Xe] 4f 8 5d 6 6s 2 Correct Answer 3 Explanation Because half field subshell more stable than partial field subshell [Xe] 4f 7 5d 1 6s 2, [Xe] 4f 8 5d 0 6s 2 is wrong

Q.6 The statement that is not correct for periodic classification of elements is : Option 1 The properties of elements are periodic function of their atomic numbers. Option 2 Non metallic elements are less in number then metallic elements. Option 3 For transition elements, the 3d -orbitals are filled with electrons after 3p -orbitals and before 4s-orbitals. Option 4 The first ionisation enthalpies of elements generally increase with increase in atomic number as we go along a period. Correct Answer 3 Explanation 3p then 4s then 3d

Q.7 The period number in the long fo rm of the is equal to Option 1 Magnetic quantum number of any element of the period. Option 2 Atomic number of any element of the period. Option 3 Maximum Principal quantum number of any element of the period. Option 4 Maximum Azimuthal quantum number of any element of the period. Correct Answer 3 Explanation Maximum principle quantum numbers of any element of the period is period number of long term of periodic table & 1s 2 2s 2 2p 5 period number is 2

Q.8 Assertion : The 5 th period of periodic table contains 18 elements not 32. Reason : n = 5, l = 0, 1, 2, 3, 4. The order in which the energy of available orbitals 4d, 5s and 5p increases is 5s< 4d < 5p and the total number of orbitals available are 9 and thus 18 electrons can be accomodated. Option 1 If both assertion and reason are correct and reason is the correct explanation of assertion. Option 2 If both assertion and reason are true but reason is not the correct explanation of assertion. Option 3 If asser tion is true but reason is false. Option 4 If reason is true but assertion is false. Correct Answer 1 Explanation If both assertion and reason are correct and reason is the correct explanation of assertion.

Q.9 The elements in which electrons are progressively filled in 4 f-orbital are called Option 1 Actinoids Option 2 Transition elements Option 3 Lanthanoids Option 4 Halogens Correct Answer 3 Explanation 4f series elements is called Lanthanoids elements Q.10 La (lanthanum) having atomic number 57 is a member of : Option 1 s-block elements Option 2 p-block elements Option 3 d-block elements Option 4 f-block elements Correct Answer 3 Explanation d-block elements

Q.11 If t he aufbau principle had not been followed, Ca (Z = 20) would have been placed in the : Option 1 s-block Option 2 p-block Option 3 d-block Option 4 f-block Correct Answer 3 Explanation d-block

Q.12 Assertion : The 4f -and 5f -inner transition series of elements are placed separately at the bottom of the periodic table. Reason : (i) This prevents the undue expansion of the periodic table i.e., maintains its structure. (ii) This preserve the principles of classification by keeping elements with similar properties in a single column. Option 1 If both assertion and reason are correct and reason is the correct explanation of assertion. Option 2 If both assertion and reason are true but rea son is not the correct explanation of assertion. Option 3 If assertion is true but reason is false. Option 4 If reason is true but assertion is false. Correct Answer 1 Explanation If both assertion and reason are correct and reason is the correct explanation of assertion.

Q.13 Which of the following sets contain only isoelectronic ions? Option 1 Zn 2+ , Ca 2+ , Ga 3+ , A l3+ ☐ Option 2 K+, Ca 2+ , Sc 3+ , C l- ☒ Option 3 P3-, S 2-, C l-, K + ☒ Option 4 Ti 4+ , Ar , Cr 3+ , V 5+ ☐ Explanation (a) Zn 2+ (28) Ga 3+ (28) Ca 2+ (18) Al 3+ (10) (b) K+(18) Sc 3+ (18) Ca 2+ (18) Cl -(18) (c) P3-(18) S 2-(18) Cl -(18) K +(18) (d) Ti 4+ (18) Ar(18) Cr 3+ (21) V 5+ (18)

Q.14 In which of the following sets of elements, they have nearly the same atomic size Option 1 Li, Be, B, C Option 2 Mg, Ca, Sr, Ba Option 3 O, S, Se, Te Option 4 Fe, Co, Ni, Cu Correct Answer 4 Explanation d-block elements from Fe to Cu nearly same atomic size

Q.15 The correct order of the sizes of C, N, P, S, is Option 1 N< C < P < S Option 2 C< N < S < P Option 3 C< N < P < S Option 4 N< C < SP < Correct Answer 4 Explanation N< C < SP <

Q.16 Consider the isoelectronic species, Na +, Mg 2+ ,F - and O2-. The correct order of increasing length of their radii is ...... Option 1 F-< O 2- < Mg 2+ < Na + Option 2 Mg2+< Na + < FO < 2- Option 3 O2-< F < Na + < Mg 2+ Option 4 O2-< F - < Mg 2+ < Na + Correct Answer 2 Explanation Mg2+< Na + < FO < 2-

Q.17 In which of the following pair, both the species are isoelectronic but the first one is large in size than the second ? Option 1 S2-, O 2- Option 2 Cl -, S 2- Option 3 F-, Na + Option 4 N3-, P 3- Correct Answer 3 Explanation F-, Na +

Q.18 The correct order of ionic size of N 3-, Na +, F -, Mg 2+ and O 2- is : Option 1 Mg2+> Na + >> F - O 2- < N 3- Option 2 N3->> F - O 2- > Na + > Mg 2+ Option 3 Mg2+< Na + << F - O 2- < N 3- Option 4 N3-> O 2- >> F - Na + > Mg 2+ Correct Answer 3 Explanation Mg2+< Na + << F - O 2- < N 3-

Q.19 From the ground state electronic configuration of the elements given below, pick up the one with highest value of second ionization energy Option 1 1 s 2 2 s 2 2 p 6 3 s 2 Option 2 1 s 2 2 s 2 2 p 6 3 s 1 Option 3 1 s 2 2 s 2 2 p 6 Option 4 1 s 2 2 s 2 2 p 5 Correct Answer 2 Explanation After 1 st IE (((1s2 2s 2 2p 6 ))) →→→ Non configuration

Q.20 In which of the following pairs, the ionization energy of the first species is less than that of the second Option 1 N, P Option 2 Be +, Be Option 3 N, N - Option 4 S, P Correct Answer 4 Explanation P has half filled stability. ∴∴∴ IE is higher for P than S.

-1 Q.21 IE 1 and IE 2 of Mg are 178 and 348 kcal mol respectively. The ene rgy required for the reaction Mg((()( g)))(→→→ Mg2+((() g))) +2e - is Option 1 + 170 kcal Option 2 + 526 kcal Option 3 - 170 kcal Option 4 - 525 kcal Correct Answer 2 Explanation + 526 kcal

Q.22 For a given value of n (principal quantum number), ionization energy is highest for Option 1 d-Electrons Option 2 f-Electrons Option 3 p-Electrons Option 4 s-Electrons Correct Answer 4 Explanation Due to highest electron affinity.

Q.23 Which one of the following is true about metallic character when the move from left to right in a period and top to bottom in a group Option 1 Increases both in the period and group Option 2 Decreases both in the period and group Option 3 Decreases in the period and increases in a group Option 4 Increases in the period and decreases in a group Correct Answer 3 Explanation Conceptual

Q.24 The electronic configurations of the elements X, Y, Z and J are given below. Which element has the highest metallic character ? Option 1 X = 2, 8, 4 Option 2 Y = 2, 8, 8 Option 3 Z = 2, 8, 8, 1 Option 4 J = 2, 8, 8, 7 Correct Answer 3 Explanation Z = K which has the highest metallic character.

Q.25 The first ionisation enthalpies of Na, Mg, A l and Si are in the order: Option 1 Na< Mg > Al < Si Option 2 Na> Mg > Al > Si Option 3 Na< Mg < Al < Si Option 4 Na> Mg > Al < Si Correct Answer 1 Explanation Pairing of electrons makes the first ionisation enthalpy higher then all.

Q.26 The ionization energy of boron is less than that of beryllium because : Option 1 Beryllium has a higher nuclear charge tha boron Option 2 Beryllium has a lower nuclear charge than boron Option 3 The outermost electron in boron occupies a 2p -orbital Option 4 The 2s and 2p -orbitials of boron are degenerate Correct Answer 3 Explanation Conceptual

Q.27 Which of the f ollowing is correct order of Ist , IInd and IIIrd ionization energy of nitrogen ? Option 1 I> II > III Option 2 III> II > I Option 3 I> II < III Option 4 II> I > III Correct Answer 2 Explanation 3rd IE is always grater then 2 nd and 1 st .

Q.28 The graph of ionization energy and atomic number does not increase smoothly because Option 1 The values for Be and Mg high and this is attributed to the stability of a filled s level Option 2 The values for N and P are high due to half filled p -orbital Option 3 Both (a) and (b) are correct Option 4 None of these Correct Answer 3 Explanation Both (a) and (b) are correct

Q.29 The first ionisation energy of first atom is greater than that of second atom, whereas reverse order is true for their second ionisation energy. Which set of elements is in accordance to above statement? Option 1 C> B ☒ Option 2 P> S ☒ Option 3 Be> B ☒ Option 4 Mg> Na ☒ Explanation

-1 Passage Text The (IE) 1 and the (IE) 2 in kJ mol of a few elements designated by Roman numerals are shown below: Element (IE)1 (IE)2 A 2372 5251 B 520 7300 C 900 1760 D 1680 3380

Q.30 Which of the above elements is likely to be a reactive metal? Option 1 A Option 2 B Option 3 C Option 4 D Correct Answer 2 Explanation Because of their low IP it is highly reactive.

Q.33 Assertion : Third ionisation energy of phosphorous is larger than Sulphur. Reason : There is a larger amount of stability associated with filled s- and p- sub-shells (a noble gas electron configuration) which corresponds to having eight electrons in the valence shell of an atom or ion. Option 1 If both assertion and reason are correct and reason is the correct explanation of assertion. Option 2 If both assertion and reason are true but reason is not correct explanation of assertion. Option 3 If assertion is true but reason is false. Option 4 If reason is true but assertion is false. Correct Answer 4 Explanation If reason is true but assertion is false.

Q.34 Electronegativity values for elements help in predicting Option 1 Polarity of bonds Option 2 Dipole moments Option 3 Valency of elements Option 4 Position in the electrochemical series Correct Answer 1 Explanation Conceptual

Q.35 Which one of the following elements shows both positive and negative oxidation states? Option 1 Cesium Option 2 Fluorine Option 3 Iodine Option 4 Xenon Correct Answer 3 Explanation Iodine I 5+ , I -1

Q.36 The electronegativity of the following elements increases in the order : Option 1 C< N < Si < P Option 2 Si< P < C < N Option 3 N< C < P < Si Option 4 C< Si < N < P Correct Answer 2 Explanation Si< P < C < N

Q.37 Which of the following effects the electronegativity of an atom? Option 1 s-Character in hybridization ☒ Option 2 Multiplicity of bond between atoms ☒ Option 3 Oxidation number ☒ Option 4 The number of neutrons in the nucleus ☐ Explanation Conceptual

Q.38 A, B and C are hydroxy - compounds of the elements X, Y and Z respectively. X, Y and Z are in the same period of the periodic table. A gives an aqueous solution of pH less than seven. B reacts with both strong acids and strong alkalis. C gives an aqueous solution which is strongly alkaline. Which of the following statements is/are true? I : The three elements are metals. II : The electro negativities decrease from X to Y to Z. III : The decreases in the order X, Y and Z. IV : X, Y and Z could be phosphorus, aluminum and sodium respectively. Option 1 I, II, III only correct Option 2 I, III only correct Option 3 II, IV only correct Option 4 II, III, IV only correct Correct Answer 3 Explanation A is acidic Hydroxy Compound B is amphoteric Hydroxy Compound C is basic Hydroxy Compound ∴∴∴(II) and (IV) are correct

Q.39 The electron affinities of B, C, N and O are in the order of Option 1 B< C < N < O Option 2 B< C < O > N Option 3 B< C > O > N Option 4 B> C < O < N Correct Answer 2 Explanation B< C < O > N half filled stability

Q.40 Which one of the following statement is incorrect? Option 1 Greater is the nuclear charge, greater is the electron affinity Option 2 Nitrogen has zero electron affinity Option 3 Electron affinity decreases from fluorine to iodine in the group Option 4 Chlorine has highest electron affinity. Correct Answer 3 Explanation Electron affinity decreases from fluorine to iodine in the group

Q.41 The lower electron affinity of fluorine than that of chlorine is due to Option 1 Smaller size Option 2 Smaller nuclear charge Option 3 Difference in their electronic configurations Option 4 Its highest reactivity Correct Answer 1 Explanation Smaller size

Q.42 Among halogens, the correct order of amount of energy released in electron gain (electron gain enthalpy) is: Option 1 F> Cl > Br > I Option 2 F< Cl < Br < I Option 3 F< Cl > Br > I Option 4 F< Cl < Br < I Correct Answer 3 Explanation F< Cl > Br > I

Q.43 The formation of the oxide ion, O 2- (g), from oxygen atom requires first an exothermic and then an endothermic step as shown below: O((()( g)))( +e--→ O((() g))) ; ∆ H - = -141kJ mol -1 O-((()( g)))( +e -2-→ O((() g))) ; ∆ H - = +780kJ mol -1 Thus process of formation of O 2- in gas phase is unfavourable even though O 2- is isoelectronic with neon. It is due to the fact that, Option 1 Oxygen is more electronegative. Option 2 Addition of electron in oxygen results in larger size of the ion. Option 3 Electron repulsion outweighs the stability gained by achieving noble gas configuration. Option 4 O- ion has comparatively smaller size than oxygen atom. Correct Answer 3 Explanation Electron repulsion outweighs the stability gained by achieving noble gas configuration.

Q.44 The correct order of increasing electron affinity of the following element is: Option 1 O< S < F < Cl Option 2 O< S < Cl < F Option 3 S< O < F < Cl Option 4 S< O < Cl < F Correct Answer 1 Explanation O< S < F < Cl

Q.45 Which of the following elements will gain one electron more readily in comparison to other elements of their group? Option 1 S (g) ☒ Option 2 Na (g) ☐ Option 3 O (g) ☐ Option 4 Cl (g) ☒ Explanation S (g) , Cl (g)

Q.46 Electronic configuration of some elements is given in column I and their electron gain enthalpies are given in column II. Match the electronic configuration with electron gain enthalpy. No. Column A Column B Column C Id of Additional Electronic Electron Gain Answer configuration Enthalpy / kJ mol -1 1 1s 22s 2sp 6 +48 2 1s 22s 12p 63s 1 -53 3 1s 22s 22p 5 -328 4 1s 22s 22p 4 -141 Explanation A - S B - P C - Q D - R

Q.47 Which of the following statements is/are wrong ? Option 1 Van der Waals’ radius of iodine is more than its covalent radius Option 2 All isoelectronic ions belong to same period of the periodic table

Option 3 I.E. 1 of N is higher than that of O while I.E. 2 of O is higher than that of N Option 4 The electron gain en thalpy of N is almost zero while that of P is 74.3 kJ mol-1 Correct Answer 2 Explanation All isoelectronic have different atomic number but belong to same period

Q.48 Match the correct ionisation enthalples and electron gain enthaopies of the following elements. No. Column A Column B Column C Id of Additional

Elements ∆H1 ∆ H 2 ∆ eg H Answer 1 Most reactive non 1681 3374 -328 metal 2 Most reactive 419 3051 -48 metal 3 Least reactive 2372 5251 +48 element 4 Metal forming 738 1451 -40 binary halide Explanation A - Q B - P C - S D - R

Q.49 Consider the following statements : (I) The radius of an anion is larger than that of the parent atom. (II) The ionization energy generally increases with increasing atomic number in a period. (III) The electronegativity of an element is the tendency of an isolated atom to attract an electron. Which of the above statements is/are correct ? Option 1 I alone Option 2 II alone Option 3 I and II Option 4 II and III Correct Answer 3 Explanation (I) The radius of an anion is larger than that of the parent atom. (II) The ionization energy generally increases with increasing atomic number in a period.

Q.50 Which of the following statements are correct? Option 1 Helium has the highest first ionisation enthalpy in the periodic table. ☒ Option 2 Chlorine has less negative electron gain enthalpy than fluorine. ☐ Option 3 Mercury and bromine are liquids at room temperature. ☒ Option 4 In any period, atomic radius of is the highest. ☒ Explanation (Solution in IP and radius e)