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DPP-1 Quantum Numbers DPP-1 Quantum numbers Q: 1-Write down the quantum numbers n,l and m for 2pz orbital? Q:2-Which of the following orbitals are not possible? 7s , 2d, 3f and 1p Q:3-With the increasing principal quantum number, the energy difference between adjacent energy levels in H-atom A decreases B increases C remains constant D decreases for low value of Z and increases for higher value of Z Q-4:How many electrons can fit into the orbitals that comprise the 3rd quantum shell n = 3 ? A 2 B 8 C 18 D 32 Q:5: Which of the following statements concerning the four quantum numbers is false A n gives idea of the size of an orbital B ℓ gives the shape of an orbital C ms gives the energy of the electron in the orbital in absence of magnetic field D ms gives the direction of spin angular momentum of the electron in an orbital Q:6-Which of the following statements concerning the four quantum numbers is false A The shape of an atomic orbital depends on the azimuthal quantum number B The orientation of an atomic is given by magnetic quantum number C The energy of an electron in an atomic orbital of multi electron atom depends on the principal quantum number only D The number of degenerate atomic orbitals of one type depends on the values of azimuthal and magnetic quantum numbers Q:7-The quantum number not obtained from the Schrodinger’s wave equation is A n B ℓ C m D s Q:8-The set of quantum numbers not applicable for an electron in an atom is A n = 1, ℓ= 1, m = 1, s = + 1/2 B n = 1, ℓ= 0, m = 0, s = + 1/2 C n = 1, ℓ= 0, m = 0, s = – 1/2 D n = 2, ℓ= 0, m = 0, s = + 1/2 Q:9-Maximum numbers of electrons in a subshell is given by A (2ℓ+1) B 2(2ℓ+1) C (2ℓ+1)2 D 2(2ℓ+1)2 Q:10-Which one of the following represents an impossible arrangement ? N ℓ m s A 3 2 –2 ½ B 4 0 0 ½ C 3 2 –3 ½ D 5 3 0 ½ Q:11-If n and ℓ are respectively the principal and azimuthal quantum numbers, then the expression for calculating the total number of electrons in any energy level is - A B C D Q:12-The Z-component of angular momentum of an electron in an atomic orbital is governed by the A Principal quantum number B Azimuthal quantum number C Magnetic quantum number D Spin quantum number Q-13: The correct Schrodinger's wave equation for a electron with total energy E and potential energy V Is given by A B C D None of these Q:14-For which of the following sets of quantum numbers, an electron will have the highest energy? N ℓ m s A 2 2 1 -1/2 B 4 3 -1 +1/2 C 4 1 -1 +1/2 D 5 0 0 -1/2 Q:15- In H-atom energy of electron is determined by A only n B n, ℓ C n,ℓ,m D all the four quantum numbers. Q:16-How many electron(s) in an atom can have n = 3, ℓ=2? A 1 B 2 C 5 D 10 DPP-1 Solutions Q:1 -Write down the quantum numbers n,l and m for 2pz orbital? Solution: For 2pz orbital n=2 l=1 m=0 Q:2-Which of the following orbitals are not possible? 7s , 2d, 3f and 1p Solution: For any value of principal quantum number (n) l holds value 0 to n-1 We know For s , l=0 p, l=1 d, l=2 f, l=3 Hence 2d , 3f and 1p are not possible. Q:3-With the increasing principal quantum number, the energy difference between adjacent energy levels in H-atom A decreases B increases C remains constant D decreases for low value of Z and increases for higher value of Z With the increasing principal quantum number, the energy difference between adjacent energy levels in H-atom Solutions: For Hydrogen atom energy is given as: Therefore with increasing quantum number , the energy difference between adjacent energy level decreases. Q:4-How many electrons can fit into the orbitals that comprise the 3rd quantum shell n = 3 ? A 2 B 8 C 18 D 32 Sol : Maximum number of electron presents in any principal shell is given by = 2n2 For n = 3 Number of electrons = 2×(3)2 = 2×9 = 18 electron Q:5-Which of the following statements concerning the four quantum numbers is false A n gives idea of the size of an orbital B ℓ gives the shape of an orbital C ms gives the energy of the electron in the orbital in absence of magnetic field D ms gives the direction of spin angular momentum of the electron in an orbital Sol : ms or s is known as spin Quantum number. ms gives the information about the direction of spinning of the electron present in any orbital. Hence option (C)is false statement. Q:6-Which of the following statements concerning the four quantum numbers is false A The shape of an atomic orbital depends on the azimuthal quantum number B The orientation of an atomic is given by magnetic quantum number C The energy of an electron in an atomic orbital of multi electron atom depends on the principal quantum number only D The number of degenerate atomic orbitals of one type depends on the values of azimuthal and magnetic quantum numbers Solution: The energy of an electron for Hydrogen or hydrogen like particles( containing only one electron) is depends upon only principal quantum number. But for multielectron particles the energy is depend upon both principal quantum number (n) and azimuthal quantum (l) Q:7-The quantum number not obtained from the Schrodinger’s wave equation is A n B ℓ C m D s Sol : The first three Quantum Number i.e. principal Quantum Number(n ), Azimuthal Quantum numbers(l ) and Magnetic Quantum number(m) are derived from the Schrodinger’s wave equation. Spin Quantum Number(s) is not derived from Schrodinger’s wave equation Q:8-The set of quantum numbers not applicable for an electron in an atom is A n = 1, ℓ= 1, m = 1, s = + 1/2 B n = 1, ℓ= 0, m = 0, s = + 1/2 C n = 1, ℓ= 0, m = 0, s = – 1/2 D n = 2, ℓ= 0, m = 0, s = + 1/2 Sol : For n = 1 ℓ = 0 to ( n-1) = 1-1 = 0 Hence option (A) is not applicable Q:9-Maximum numbers of electrons in a subshell is given by A (2ℓ+1) B 2(2ℓ+1) C (2ℓ+1)2 D 2(2ℓ+1)2 Sol : Maximum number of electrons in subshell is given by = 2(2ℓ+1) Where ℓ is Azimuthal Quantum number. Q:10-Which one of the following represents an impossible arrangement ? N ℓ m s A 3 2 –2 ½ B 4 0 0 ½ C 3 2 –3 ½ D 5 3 0 ½ Sol : For n = 3 ℓ =0 to n-1 ℓ = 3-1 = 2 and m lies between = -ℓ to +ℓ = -2,-1,0,1,2 Therefore option (C) is impossible. Q:11-If n and ℓ are respectively the principal and azimuthal quantum numbers, then the expression for calculating the total number of electrons in any energy level is - A B C D Sol : For principal Quantum number = n Azimuthal Quantum Holds value(ℓ ) =0 to (n-1) Number of orbitals = 2(l+1) And one orbital can holds maximum two electrons Hence, Maximum number of electron in subshell is given by Q:12-The Z-component of angular momentum of an electron in an atomic orbital is governed by the A Principal quantum number B Azimuthal quantum number C Magnetic quantum number D Spin quantum number Sol : Magnetic Quantum number give the Quantized value of Z-component of the angular Momentum. Q:13-The correct Schrodinger's wave equation for a electron with total energy E and potential energy V Is given by A B C D None of these Solution: Q:14-For which of the following sets of quantum numbers, an electron will have the highest energy? N ℓ m s A 2 2 1 -1/2 B 4 3 -1 +1/2 C 4 1 -1 +1/2 D 5 0 0 -1/2 Sol : The energy of an orbital depends upon the sum of the principal Quantum Number (n) and the Azimuthal Quantum Number (ℓ) i.e., (n +ℓ) rule. Higher the value of (n+ℓ), higher will be the energy A⟶n + ℓ = 2 + 2 = 4 B ⟶n+ℓ = 4 +3 = 7 (Highest) C ⟶n+ℓ= 4 +1 = 5 D ⟶n+ℓ = 5+0 =5 Q:15-In H-atom energy of electron is determined by A only n B n, ℓ C n,ℓ,m D all the four quantum numbers. Sol : For Hydrogen atom, Energy is given by n= principal shell Hence option (A) is correct Q:16-How many electron(s) in an atom can have n = 3, ℓ=2? A 1 B 2 C 5 D 10 Sol : Number of electron for n = 3, ℓ = 2 is given by: = 2(2ℓ+1) = 2(2×2+1) =2(5) = 10 Join Vedantu JEE Telegram channel NOW! 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