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Atomic Structure JEE Main Problems and Solutions 

Chapter -2 Structure of atom practice questions

Here is the complete exercise (past year JEE problem) from Chapter -2 Structure of Atom of  class 11 with answers.

Chapter-2 , Structure of Atom is an important topic both for JEE and CBSE . Practice these questions and make your preparation more strong.

The exercise on chapter-2 structure of atom consists of mcq questions with single correct answer and integer value type questions with integer value correct answer

You can find the answers to these questions below this exercise ( in the bottom of this page ).
If you want to download the complete exercise in PDF format, you can do so. Just scroll down the page and download the PDF from the end of this exercise.


Chapter-2, Structure of Atom Practice exercise for JEE ,or CBSE,


1.The orbital angular momentum of an electron in 2s orbital is

(A) +1/2(h/2π)

(B) zero

(C) h/2π

(D) √2(h/2π)


2.The number of nodal planes in a px orbital is

(A) one 

(B) two

(C) three 

(D) zero


3.The number of radial nodes of 3s and 2p orbitals are respectively

(A) 2,0 

(B) 0,2

(C) 1,2 

(D) 2,1


4. Which of the following sets of quantum numbers is correct for an electron in the  4f  orbital

(A) n=4 , l=3, m=+1, s=+1/2

(B) n=4 , l=4, m=-4, s=-1/2

(C) n=4 , l=3, m=+4, s=+1/2

(D) n=3 , l=2, m=-2, s=+1/2


5. Which of the following statements is wrong? The probability of finding the electron in px  orbital is

(A) Maximum on two opposite sides of the nucleus along x-axis

(B) zero at the nucleus

(C) same on all the sides around the nucleus

(D) zero on the z-axis 


6.Which of the following sets of quantum numbers represents the highest energy of an  atom?

(A) n=3 , l=0, m=0, s=+1/2

(B) n=3 , l=1, m=1, s=+1/2

(C) n=3, l=2, m=1, s=+1/2

(D) n=4 , l=0, m=0, s=+1/2


7. Bohr’s model of atom is not in agreement with

(A) Line spectra of hydrogen atom

(B) Pauli’s principle

(C) Planck’s theory 

(D) Heisenberg’s principle


8. Which of the following statements is correct?

(A) All electromagnetic radiations do not possess the same velocity

(B) Matter waves are associated with electrical and magnetic fields

(C) Matter waves and electromagnetic radiations are alike

(D) The velocity of matter wave is generally less than that of light


9.Calculate the wavelength associated with a proton moving at 1×10³ m/s ( mass of proton=1.67× 10^-27 kg and h =6.63 × 10^-34 Js)

(A) 0.40 nm 

(B) 2.5 nm

(C) 14.0 nm 

(D) 0.32 nm


10.The transition of electrons in H atom that will emit maximum energy is

(A) n3––––> n2

(B) n4––––> n3

(C) n5––––> n4 

(D) n6––––> n5


11. A gas absorbs a photon of 355 nm and emits at two wavelengths. If one of the emissions is at 680 nm ,the other is at

(A) 1035 nm 

(B) 325 nm

(C) 743 nm 

(D) 518 nm


12. The radius of which of the following orbits is same as that of the first Bohr’s orbit of hydrogen atom ?

(A) He+(n=2) 

(B) Li2+ (n=2) 

(C) Li2+ (n=3) 

(D) Be3+ (n=2)


13.The wave number of first line of Balmer series of hydrogen is 15200 cm-1. The wave number of the first Balmer line of  Li1+ ion is

(A) 15200 cm-1

(B) 60800 cm-1

(C)76000 cm-1

(D) 136,800 cm-1


14. If the speed of electron in Bohr first orbit of hydrogen atom be x, then speed of the electron in 3rd orbit is

(A) x/9 

(B) x/3 

(C) 3x

(D) 9x


15.In an atom , an electron is moving with a sped of 600 m/s with an accuracy of 0.005%.Certainity with which the position of the electron can be located is, 
( mass of electron= 9.1× 10^-31 kg, h= 6.6× 10^-34 kg m² s-1)

(A) 5.10× 10^-3 m

(B) 1.92× 10^-3 m 

(C) 3.84× 10^-3 m 

(D) 1.52× 10^-4 m 


16. Which of the following statements in relation to the hydrogen atom is correct?

(A) 3s-orbital is lower in energy than 3p-orbital

(B) 3p-orbital is lower in energy than 3d-orbital

(C) 3s and 3p orbitals are of lower energy than 3d orbital

(D) 3s, 3p and 3d orbitals all have the same energy


17. The energy of second Bohr orbit of the hydrogen atom is –328 kJ mol–1, hence the energy of fourth Bohr orbit would be

(A) –41 kJ mol–1 

(B) –1312 kJ mol–1

(C) –164 kJ mol–1 

(D) –82 kJ mol–1


18. The relationship between energy E1, of the
radiation with a wavelength 8000 Å and the energy E2 of the radiation with a wavelength 16000 Å is

(A) E1 = 6E2 

(B) E1 = 2E2

(C) E1 = 4E2 

(D) E1 =1/2 E2

19. Which is not true with respect to cathode rays?

(A) A stream of electrons

(B) Charged particles

(C) Move with speed as that of light 

(D) Can be deflected by magnetic fields

20.The most probable radius (in pm) for finding the electron in He+  is

(A) 0·0 

(B) 52·9

(C) 26·5

(D) 105·8

Also Read : P Block Element Class 12 Notes

Integer value type questions

1. The maximum number of electrons that can have principal quantum number,n=3 and  spin quantum ms = -1/2,. is __________________.

2. In an atom , the total number of electrons having quantum number, n=4, |m|=1, and  ms=-1/2 is ______________.

3. The energy required to excite one litre of hydrogen gas at 1 atm and 298 K to the first excited state of atomic hydrogen (the energy for the dissociation of H-H bond is 436 kJ/mol) is ___________________.

4. The number of waves made by a Bohr electron in one complete revolution in its 3rd  orbit are______________________.

5. If the wavelength of high energy transition of hydrogen atom is 91.2nm, then the  corresponding wavelength of He atoms is_____________.



Answers to the above exercise is given here . Check your answers 

Answers

1.  (B)    6.  (C) 11. (C) 16. (D)
2.  (A) 7.  (D) 12. (D) 17. (D)
3.  (A) 8.  (D) 13. (A) 18. (B)
4.  (A) 9.  (A)      14. (B) 19. (C)
5.  (C) 10. (A)      15. (B) 20. (C)

        Integer value type questions- Answers   
                       
(1) 9                         (3). 98.17 kJ              (5). 22.8nm

(2) 6                                  (4). 3