Atomic Structure Questions and Answers

18 The distance between 4th and 3rd Bohr orbits of He is b 1 322 x 10 10 m c 1 851 x 10 10 m a 2 645 x 10 10 m Vors Cas None of these

In Bohr s stationary orbits a electrons do not move b electrons move emitting radiations c energy of the electron remains constant Yangular momentum of the electron is h 2 5 Jo vii

C 1 2 The radius of which of the following orbit is same as that of the first Bohr s orbit of hydrogen atom A He n 2 C Li2 n 3 n ron Z B Li n 2 D Be n 2 2004 in configuration 1s it would have energy lower than that of the 2

23 Select the incorrect graph for velocity of e in an orbit vs Z n a V sad to zibst b 1 n 890 d c 1 sib dom at 107 bo z and n dro d a de ribet af mis avi n

Column I A No of orbitals in the n shell B Max no of electrons in a subshell C No of subshells in n shell Column II P 2 2 1 Q n R 2 1

The wavelength of a certain line in the Paschen series in 1094 4 nm of H atom What is the value of high for this line

column correctly Column I A The radial node of 5s atomic orbital is B The angular node of 3d atomic orbital is C The sum of angular node and radial node of 4d atomic orbital D The angular node of 3p atomic orbital is Column II P 1 Q 4 R 2 S 3

The number of spherical nodes in 3p orbitals is b three a one c two d zero

Which general electronic configuration of the element does not represent a non metal metel is in s p 1 ns np 2 ns n 1 d 10 np5 3 ns 2 n 1 d1 10 4 ns n 1 0 10 np1 6 d black metal

Consider the following six electronic configurations remaining inner orbitals are completely filled and mark the incorrect option 3s 3p 3s 1 4s IV 3p II 1 3d 4s 4p GHI V I CH a Stability order II I IV III 3s III T 4s VI 1 3d TIT 3d b Order of spin multiplicity IV III I II c V does not violate all the three rules of electronic configuration d If VI represents A and A when kept near a magnet acts as diamagnetic substance 1 Which of the following set of quantum numbers belong to highest energy

Question Is the specie paramagnetic Statement 1 The atomic number of specie is 29 The charge on the specie is 1 Statement 2 A Statements 1 alone is sufficient but statement 2 is not sufficient B Statement 2 alone is sufficient but statement 1 is not sufficient C Both statement together are sufficient but neither statement alone is sufficient D Statement 1 2 together are not sufficient

Naturally occurring thallium consists of two stable isotopes T1203 and T1205 atomic masses 203 0 and 205 0 respectively and has an average atomic mass of 204 4 What is the percentage of T1 205 A 14 0 B 70 C 50 0 D 64 7 Hai l NOL

2 8 15 The potential energy of an electron in the hydrogen atom is 6 8 eV Indicate in which excit state the electron is present a first b second c third d fourth lestron present in N shell of the Be ion 34

Given in hydrogenic atom V E K stand for radius potential energy total energy and kinetic energy in nth orbit Find the value of U v x y of column I from column II JEE 2006 Column I A B C U In Vn Kn oc Ex ZY Z Atomic number Orbital angular momentum electron Column II P 1 Q R 2 To

4th 5th and 6th period elements can form complex compounds by coordinate covalency due to the presence of vacant d orbitals

6 del of the Atom The set of quantum numbers not applicable to an electron fours are nems 1 1 1 1 3 1 0 0 1 2 1 2 1 0 0 1 1 2 4 2 0 0 1 2

Statement 1 Energy emitted when an electron jump from 5 2 energy level is less than when an electron jump from 2 1 in all H like atom Statement 2 The total energy difference between 1st 2nd energy level is greater than that of any two energy level provided level 1 is not part of those two energy levels A Statement 1 is true statement 2 is true and statement 2 is correct explanation for statement 1 B Statement 1 is true statement 2 is true and statement 2 is NOT the correct explanation for statement 1 C Statement 1 is true statement 2 is false D Statement 1 is false statement 2 is true

Question 14 What is the coordination entity formed when excess of aqueous KCN is added to an aqueous solution of copper sulphate Why is it that no precipitate of copper sulphide is obtained when H S g is passed through this solution with OYCOSS KCN Cu ions are absent in the

387 An atom has four unpaired electrons The total spin of this atom will be TCO A 1 B 1 5 C 2 Which of the following statement is wrong 20 D 4

The electronic configuration having maximum difference in first and second ionization energies is 1 1s 2s 2p 3s 2 1s 2s 2p 3s 3p 3 1s 2s 2p 3s 3p 4 1s 2s 2p 3s

B The maximum number of orbital s that can be identified with the following quantum numbers is n 2 1 1 m 1 1 2 3 3 2 1 4 4

7 The energy required to remove an electron from th surface of sodium metal is 2 3 eV What is the longe wavelength of radiation with which it can sho photoelectric effect

The ground state energy of hydrogen atom is 13 6 eV Consider an electronic state of He whose energy azi muthal quantum number and magnetic quantum number are 3 4 eV 2 and 0 respectively Which of the following statement s is are true for the state A It is a 4d state B It has 2 angular nodes C It has 3 radial nodes D The nuclear charge experienced by the electron in this state is less than 2e where e is the magnitude ose of the electronic charge

Which of the following shapes of SF4 is more stable and why On F S F i F F S F ii F F

69 The first emission line of hydrogen atomic spectrum in the Balmer series appears at R Rydberg constant 1 3 5R 36 7R 1 cm 144 cm 1 2 3R T cm 9R 4 cm 1 400

An electron in hydrogen atom falls from sixth excited state to first excited state Total possible lines emitted in the visible region are 2 15 4 21 1 Zero 3 5

30 Calculate the wavelength and energy of radiatio emitted for the electronic transition from infinity to the stationary state of the hydroge atom

36 The following transition occurs when Lithium atoms are sprayed into hot flame The various steps are numbered for identification 2s 2p 3d Which of these transitions result in emission of light A I II V B III V III 3p IV 4s 3p C III IV V D All

21 Find the quantum no n corresponding to excited state of He ion if on transition to the gr state that ion emits two photons in succession wavelengths 108 5 and 30 4nm

3 n p d bond 4 Three p d bonds Bond distance in HF is 9 17 x 10 11 m Dipole moment of HF is 6 104 x 10 30 Cm The percent ionic character in HF will be electron charge 1 60 x 10 9 C JEE MAINS 2013 On line 3 35 5 1 61 0 2 38 0 4 41 5 The shape of IF is JEE MAINS 2013 On line

Element A has 3 electrons in the outermost orbit and element B has 7 electrons in the outermost orbit The formula of the compound formed between A and B would be 1 A B3 3 A B 2 A3B6 4 AB3

79 Observe the given boundary surface diagrams of two orbitals I and II and choose the correct option Z II I d22 II dyz b I d II d a I d c I I dz II d yz II d d I dxy II dxz

7 Which d orbital has different shape from rest of al d orbitals 16 ertainty of b da d day or dys

73 If the circumference of Bohr s 3rd orbit in th hydrogen atom is 2 54 pm then the de Brogli wavelength of the electron is 1 8 5 10 13 m V E 3x108 3 717 2 0 85 10 11 m 3 2 54 10 12 m 4 0 25 10 13 m 05X10 7 x h 26x10 34

Electromagnetic radiation of wavelength 242 nm to ionise the sodium atom Calculat energy of sodium in kJ mol just sufficient the ionisation

4 The kinetic energy of an electron in H like atom i 6 04 eV Find the area of the third Bohr orbit to which this electron belong Also report the atom

nic ns sity me ng OW 16 Which orbital diagram gives an insight to the highest ionization energy 2 N 1s 1s 1 1s 11 2s 2p 4 2s 2p 5 7 4 1s S 2s N 2s 2p N11 2p E

1 34 What are the number of protons neutrons and electrons in the following isotopes a H b 4 N 26 c Si 14 d 70 304

3 Square planar 54 Zero overlap takes place between which of the following if x axis is the inter nuclear axis 1 1s and 2s 3 2p and 2p 2 2p and 2s Li 4 2p and 1s S S CHECE

What is the energy kJ mol associated with the de excitation of an electron from n 6 ton 2 in He ion a 1 36 10 b 1 36 10 c 1 16 10 d 1 78 x 10

Molecular shapes of SF4 CF4 XeF4 are a the same with 2 0 and 1 lone pairs of electrons respectively b the same with 1 1 and 1 lone pairs of electrons respectively c different with 0 1 and 2 lone pairs of electrons respectively d different with 1 0 and 2 lone pairs of electrons respectively

Maximum efficiency of cationic hydrolysis will be shown by 1 Al 3 2 Ga 3 3 Tl 1 4 Tl 3

In Bohr s model of H atom what will be shortes wave lenth in paschen series 1 820 8 nm 3 520 8 nm 2 100 8 nm 4 700 8 nm

For an atom with atomic number 14 the number of orbits and orbitals in which electrons are present are respectively a 3 6 c 7 3 b 6 3 d 3 8

10 155 Not considering the electron spin the degeneracy of first excited state n 2 of H atom is a 2 b 3 c 4 d 8

4 Fluorine is stronger oxidizing agent than chlorine in aqueous solution This can be attributed to the property A heat of dissociation B electron affinity D heat of hydration C ionization potential Election offinity of the elements or ions is correctly shown in

When the value of azimuthal quantum number is 3 the maximum and minimum values of spin multiplicity are a 1 8 c 6 1 b 8 1 d 7 0

If an electron can have three values of spin quantum numbers 0 and which of 1 1 2 2 the following statement would be correct a Li would have in the first period of the periodic table b The total number of elements is the second period would have been ten c There would have been 27 elements in the fourth period of periodic table d Number of periods would have been less than the in modern periodic tabl

5 Select the incorrect statement about cathode rays a They travel from cathode to anode b They travel in a straight line in the absence of an external electrical or magnetic field c Their nature is independent of the materials of cathode d Their nature is dependent on the nature of the gas present

v For each value of n k may have n different values These are 1 2 3 n Thus for the Bohr orbit with n 4 there are four Sommerfeld orbits three elliptical orbit one circular orbit with k 1 2 3 and 4 When k 4 the elliptical orbit reduces to a circular orbit Sommerfeld thus introduced the concept of subshells in a principal quantum shell The difference in energy between any two subshells is quite small The fine structure of hydrogen spectrum can be explained by assuming several transitions between several subshells each characterised by different values of k but same value of n n 4 k 4 n 4 k 3 n 4 k 2 n 4 k 1