Atomic Structure Questions and Answers

1 d Find the de Broglie wavelength of the electrons that have been accelerated from rest through a potential difference of 40 kV Given electronic charge e 1 602x10 19 C me 9 109x10 31 kg 3

2 d A monochromatic X ray beam whose wavelength is 0 0558 nm is scattered in Compton scattering through an angle 46 Calculate the wavelength of the scattered beam Given h 6 626x 10 34 J s mo rest mass of electron 9 1x10 31 kg c speed of light 2 998 108 m s 4

Let s consider the case of nitrogen atoms which have the electronic configuration 18 28 2p in the ground state a Assume for now that the electrons are distinguishable particles so you don t have to worry about the symmetry of wavefunctions If we ignore the interaction between the electrons or spin orbit coupling effects what are all possible values for the total electronic quantum numbers S L and J of the highest occupied electronic shell in the ground state Here S is the total electronic spin L the total angular momentum and J the quantum number of J L S Use the spectroscopic notation 25 1L for all possible states b Now using the first Hund s rule and restoring indistinguishibility what is the total spin S of the highest occupied electronic shell in the ground state Is the spin part of the three electron ket state symmetric or antisymmetric under exchange What about the orbital part

1 For the electron in d orbital the spin angular 73 momentum is 110110 2 How many orbitals are associated with 4th 1 3 3 h 22n 15 energy 74 d eneren in scocia a fazen ETUT 1 2 2T 2 3 3 3 21 4 2 2 41 at fura

1 Compute the wavelengths for the Balmer series transitions in a hydrogen atom 3 2 all the way up to 8 2 Please write all answers in nanometers Must show all your work for at least 1 one of the transitions

In accordance with Bohr s model what is the quantum number that characterizes the earth s revolution around the sun in an orbit of radius 1 5 10 1 m with orbital speed Mass of earth 6 0 x 1024 kg 1 1 8 1076 2 2 3 1074 3 1 3 1076 4 2 6 1074

An ideal gas is expanded so that the amount of heat transferred to the gas is equal to double the decrease in enthalpy Identify option s which are corre PV12 11 constant for triatomic non linear ideal gas Cm 2Cp OTV2 13 constant for monoatomic ideal gas 7 constant

3 2 1 4 1 414 1 The mass of a particle is 100 g and its radius is 87 2 x 10 cm If its velocity is 10 cm sec with measurement the 0 0001 uncertainty in uncertainty in its position is 1 5 2 x 10 m 3 5 2 x 10 m de confic 2 5 2 x 10 m 4 5 2 x 10 m 3 2 1 30 0001 feffurcan grit 1 5 2 x 10 m 3 5 2 x 10 m 4 1 414 1 102 104 10 estionpap 2 5 2 10 4 5 2 10 m m

Name the members of the lanthanoid series which exhibit 4 oxidation states and those which exhibit 2 oxidation states Try to correlate this type of behaviour with the electronic configurations of these elements

How many orbitals are associated with 4th energy 74 level 1 4 2 9 3 16 4 7 2 2 1 4 2 4T 2 9 2 2m 3 16 4 7

If a particle of mass 1 mg is moving with a velocity of 400 ms then the de Broglie wavelength of the moving particle will be h 6 6 x 10 34 Js 1 65 x 10 32 m 1 65 x 10 33 m 1 65 10 30 m 1 65 10 36 m

TYPE questions Each question has 4 choices 1 Read More Polarity in a molecule and hence the dipole moment depends primarily on electronegativity of the constituent atoms and shape of a molecule Which of the following has the highest dipole moment O CO2 O HI O H 0

According to VBT which of the following overlapping results pi bond covalent bond in 0 molecule formation when z axis is internuclear axis 1 2s 2s 1 III 1s 1s V 2pz 2pz Question Type Single Correct Type 2 II V 3 II IV II 2px 2px IV 2py 2py 4 IV V

4 Which of the following is correctly matched Orbital a 4 f b 4 s c 3 d d 3 p Ans c Nodal property 2 radial node 0 nodal plane 2 nodal plane 3 radial node Hint Number of nodal plane 1 Number of nodal plane of 3d orbital 2

For H atom the energy required for the removal of electron from various sub shells is given as under 3s 3p 3d 1 0 0 The order of the energies would be 2 Question Type Single Correct Type 3 4 E E2 E3 E3 E2 E E E E E2 E3 None of these n E3 0

Mg Which one of the following set of quantum numbers is not possible for 4p electron 2019 1 a n 4 7 1 m 1 m 2 b n 4 1 m 0 m S c n 4 1 m 2 m d n 4 1 m 1 m N N

Uncertainty in the position of an electron mass 9 1 x 10 31 kg moving with a velocity of 300 ms 1 accurate upto 0 001 will be uestion Type Single Correct Type 1 5 76 x 10 2 m 2 3 4 1 92 x 10 m 3 84 x 10 2 m 19 2 10 2 m

3 2 83 Square planar 4 1 73 Square planar A compound of vanadium chloride has spin only 63 magnetic moment of 1 73 BM The formula of molecule is 1 VCI 2 VCI 3 VCL 4 VCI 3 2 83 WARCIA 4 1 73 of 1 73 BM 1 VCI 2 VCI 3 VCL 4 VCI

ALLEN In an atom an electron is moving with a speed 75 of 600 m s with a uncertainty of 0 05 uncertainty in position of electron can be located is h 6 6 x 104 Kg m s mass of H electron 9 1 x 10 Kg 1 5 10 x 10 m 3 3 84 x 10 m m 2 1 92 x 10 m 4 1 52 x 10 m van 600 mis f 0 05 BRAI V C h 6 6 10 9 1 10 Kg 1 5 10 x 10 m 3 3 84 10 m Kg m s TNT 2 1 92 10 m 4 1 52 10 m

3 K Fe CN C13 4 K Fe CN Which of the following option is correct 1 Ce solution are widely used as oxidizing agent in volumetric analysis 2 Ce is diamagnetic ion while Yb is paramagnetic ion 3 All the lanthanides are much more reactive than aluminium 4 Both 2 and 3 are correct 3 K Fe CN C1 4 K Fe CN 49 faffefaccy 1 fad C face f 2 Cafe Y 34 32 1 3 2153 fafen af den streife fefe 4 2 3

In which of the following transition maximum energy radiation will be emitted for He ion estion Type Single Correct Type 1 2 3 4 n 5 to n 2 n 3 to n 1 n 7 to n 3 n 8 to n 4

4 5 3 For given transitions order of wavelength of 49 feug vi for free trained a photon emitted will be A 6 4 C 3 1 1 AAA 2 Ac Ap A 3 B 4 2 D 2 1 A 6 4 C 3 1 1 A An A A 2 A Ap A A B 4 2 D 2 1

Which of the following sets of quantum number is not possible Question Type Single Correct Type 1 2 3 4 n 3 l 2 m 0 ms 1 2 n 3 l 0 m 0 ms 1 2 n 3 l 0 m 1 m 1 2 n 3 l 1 m 0 ms 1 2 Your Answer Status Incorrect

4 X 1 Find the uncertainty in position of an electron if the uncertainty in velocity is 50 of uncertainty in position Question Type Single Correct Type 1 2 3 h 3 m 1 414 h 7m English h m Review

s pd f e Decreasing effective nucical ii Within a shell the effective nuclear charge decrease with increase in the azimuthal quantum of the electron Isrladire un ns np nd nf 1 0 7 1 1 2 1 3

The energy required for the excitation of 1 10 liter of hydrogen gas at one atmosphere pressure and 298K to the first excited state of atomic hydrogen approximately B DE of H 436 KJ mole is A 98 56 KJ B 108 KJ C 76 KJ D 126 25 KJ

If ao be the radius of first Bohr s orbit of H atom the de Broglie s wavelength of an electron revolving in the third Bohr s orbit will be B 4 D None of these A 6 26 o A A You Missed

The wavelengths of the Ka X ray radiations from two sources P and Q are 1 50 ar 75 A 1 A 10 10m Then most likely A P 41Nb Q 29 Cu C P 29Cu Q 41 Nb B P 29Cu Q 47 Ag D P 41Nb Q 27 Co

ALLEN 0 1 mole of each of A B and A B compounds 69 have mass of 4g and 8g respectively What are the atomic masses of A and B respectively in amu 1 20 10 2 40 30 3 30 40 4 10 20 A B A B 4g 8g 0 1 AB am 1 20 10 2 40 30 3 30 40 4 10 20 AM

9 a Elements A B C and D have atomic numbers 12 19 29 and 36 respectively On the basis of electronic configuration write to which group of the periodic table each element belongs b Predict the blocks to which these elements can be classified Also predict their periods and groups c Which of these are representative elements

When a mole of photons of wavelength 5000A incident of lodine molecules present in 1Lt container it shows pressure of 8 21 atm at 300K then calculate kinetic energy of particles present in KJ given bond NA 6 x 1023 dissociation energy of iodine molecule is 45 6KJ per mole planks constant is 6 6X10 9

Which is correct statement about proton A proton is the nucleus of deuterium B proton is alpha particles C proton is ionized hydrogen molecules D proton is ionized hydrogen atom

Species Het Li Be 3 H He No of orbit radius in A Velocity of n of orbit electron m sec 2 1 587 4 36 x 10 Total energy of Pot Energy of Kinetic Energy electron eV electron eV of electron eV 6 8 3 4

Assuming nuclei and atoms to be spherical their radii are known to be of the order of 10 13 cm and 10 8 cm respectively The fraction atomic volume occupied by the nucleus would be A B C D 10 14 10 15 10 16 Marks 4 00 10 17

Which of the following statements is correct for spin quantum number I 2 indicates clockwise spin 1 2 indicates anti clockwise spin

If in earlier days there were not any adv ance technology then how scientists w here able to discover the different types of elements and how the were also abl e to find out the atomic number and ato mic mass of elements

The wave functions of 1s and 2s atomic orbitals possess Same angular radial parts Same radial part but different angular part

Note Magnetic quantum number also represents quantized value of z component of angular momentum of the electron in an orbital through the expression Lz m h 2 If 0 is the angle between z axis and angular momentum vector Lz L cos 0 h m 21 7 1 2 1 2 2 1 1 1 cos 0 m cos e

101 The energy functional from a trial wave function is E a a 3a 6 The variationally optimized energy is a 2 b 3 100 8 c N W is c

0 In the hypothetical molecule AX L where A is central atom X is surrounding atom L is lone pair n is the number of lone pair for which possible value of n will the dipole moment of the molecule be minimum

4 2l 2 9 The possible exchanges for a de configuration is 1 4 2 10 3 8 4 6

Which of the following statements is are correct 1 There are 5 orbitals in the subshell 2 The d orbitals can accommodate 14 electrons 3 The first shell contain s and p orbitals 4 The s orbital can accommodate 2 electrons 1 and 4 O2 and 3 3 and 4

13 3 The ions O F Na Mg2 and Al are isoelectronic Their ionic radii show a a decrease from O to F and then increase from Na to Al b a significant increase from O to Al c a significant decrease from O to Al d an increase from O2 to F and then decrease from Na to Al 3

Which of the following statements is correct a Xion is larger in size than X atom b Xion is larger in size than X atom c X and Xions are equal in size d Xion is larger in size than X ion

09 A number is chosen from all numbers of digits can be made with the digits 0 1 2 3 4 5 Probability that the number is divisible by 3 is digits being unrepeated in the same number 1 23 A 25 4 None of these

This quantum number is designated by the symbol m To explain splitting of a single spectral line into a number of closely spaced lines in the presence of magnetic field Zeeman effect Linde proposed that electron producing a single line has several possible space orientations for the same angular momentum vector in a magnetic field i e under the influence of magnetic field each subshell is further sub divided into orbitals Magnetic quantum number describes the orientation or distribution of electron cloud For each value of l the magnetic quantum number m may assume all integral values from to including zero i e total 27 1 values

3 JAY V 2751 51 The number of angular nodes in 3d orbital is 2 2 1 1 3 0 4 3 52 In the reaction 2NaOH H PO Na HPO 2H O the equivalent mass of H PO is

A certain dye absorbs light of 1 4530 and then fluorescence light of 5080 Assuming that under given conditions 47 of the absorbed energy is re emitted out as fluorescence calculate the ratio of number of quanta emitted out to the number of quanta absorbed A photon of 300 nm is absorbed by a gas and then re emits two photons One re remitted photon has wave

Plancks Quantum Theory Photoelectric Effect 1 Assume that 10 17 J of light energy is needed by the interior of the human eye to see an object How ma photons of green light 2 495 nm are needed to generate this minimum energy B 30 C 35 A 25 D 40

When electromagnetic radiation of wavelength 300 nm falls on the suface of sodium electrons are emitted wi a kinetic energy of 1 68 x 105 J mol What is the minimum energy needed to remove an electron fro sodium What is the maximum wavelength that will cause a photoelectron to be emitted A 908 nm B 517 nm C 1010 nm D 205 nm