Free Atomic Structure MCQs with Answers
922 Atomic Structure MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Atomic structure covers the discovery of the proton, Planck's quantum theory, hydrogen emission spectra and the evidence for quantized energy levels. You will use quantum numbers to describe orbitals, distinguish s, p, d and f orbital shapes, and write electronic configurations, including the correct order of electron filling.
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922 questions · page 33 of 47
- A. 12
- B. 15
- C. 5
- D. 22
Explanation: The maximum number of emission lines when the excited electron of a H atom in n = 6 drops to the ground state is 2(n−n)(n−n+1) = 25×6 =15…
Correct answer: 15- A. diamagnetic
- B. paramagnetic
- C. ferromagnetic
- D. none of these.
Explanation: Chromium (Cr) with an atomic number of 24 has an electronic configuration of 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d⁵.
Correct answer: paramagnetic- A. 4215 A0
- B. 1437 A0
- C. 3942 A0
- D. 3647 A0
Explanation: Shortest wavelength means maximum energy. Therefore, the electronic transition involved should be :
Correct answer: 3647 A0644. The electronic configuration of an element is 1s2, 2s2, 2P1x, 2P1y, 2P1z.This represesnts a/an:
- A. Ground state
- B. Excited state
- C. Hybridized state
- D. Molecular state
Explanation: The ground state of an atom is its most stable and lowest energy electron configuration.
Correct answer: Ground state- A. 2:1
- B. 1:2
- C. 1:1
- D. 1:4
Explanation: Option A is correct.The ratio of e/m values of a proton and an alpha particle is 2:1. The charge of a proton is +1, and its mass is 1 u.
Correct answer: 2:1- A. 1.76 x 10^23 C/ kg
- B. 1.76 x 10^11 C/kg
- C. 1.76 x 10^-31 C/kg
- D. 1.76 x 10^7 C/kg
Explanation: Option B is correct.The e/m ratio of cathode rays is 1.76 x 10^11 C/kg.
Correct answer: 1.76 x 10^11 C/kg- A. K (19)
- B. V (23)
- C. Ti(22)
- D. Ni (28)
Explanation: According to Aufbau's principle the elcetrons should be filled itno the orbitals according to increasing energy levels.
Correct answer: K (19)- A. 2
- B. 18
- C. 8
- D. 32
Explanation: Option D is correct . N is the fourth shell and can accomodate a maximum number of 32e. We can find this by using formula 2n2
Correct answer: 32- A. Less
- B. Greater
- C. Equal
- D. Difficult to predict
Explanation: Positive rays are formed when high speed electrons collide with gas molecules and knock off there electrons making them positively charge…
Correct answer: Less- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The correct four quantum numbers for an electron in the K-shell are: Principal quantum number (n) = 1 Azimuthal quantum number (l) = 0…
Correct answer: Option C- A. s>p>d>f
- B. f>d>p>s
- C. p>s>f>d
- D. d>f>s>p
Explanation: Smaller the size of sub-shell and lower the enrgy level, higher will be the penetration power.
Correct answer: s>p>d>f- A. 4p
- B. 4f
- C. 4d
- D. 5s
Explanation: Principal Quantum number shows the orbit is 4 and Azimuthal quantum number 2 shows that electron is in D subshell. So, option C is correct.
Correct answer: 4d- A. hv
- B. nh/2
- C. 2hv
- D. 1/2 hv
Explanation: According to Planck's quantum theory, The energy of the radiation absorbed or emitted is directly proportional to the frequency of the…
Correct answer: hv- A. H
- B. H+
- C. H2
- D. He
Explanation: Hydrogen ion (H+). It contains the same number of electrons as an alpha particle, i.e. 0 electrons.
Correct answer: H+- A. H
- B. H+
- C. He+1
- D. Li+2
Explanation: Bohr's theory is only applicable to hydrogen-like species containing one electron only.
Correct answer: H+- A. (n-1)d1-9ns1
- B. (n-1)d1-5
- C. (n-1)d1-10ns1-2
- D. (n-1)d1-10ns2
Explanation: d block elements have a general electronic configuration of (n-1)d 1-10ns1-2.
Correct answer: (n-1)d1-10ns1-2- A. 5 nm
- B. 500 nm
- C. 5000 nm
- D. 100 nm
Explanation: To find the wavelength of the light, we use the speed of light equation: c = λν Where c is the speed of light in a vacuum, which is…
Correct answer: 500 nm- A. 3,2,2,1/2
- B. 4,1,0,1/2
- C. 2,2,-1/2
- D. 5,0,0,1/2
Explanation: In the context of the quantum numbers, the principal quantum number (n) indicates the energy level or shell of an electron in an atom.
Correct answer: 5,0,0,1/2- A. H & Li
- B. CI & Ar
- C. K & Rb
- D. Na & Ne
Explanation: Principal quantum number can be determined by looking at the period number.
Correct answer: CI & Ar- A. 5s > 3d > 3p > 4s
- B. 5s > 3d > 4s > 3p
- C. 3p > 3d > 5s > 4s
- D. 3p > 3d > 4s > 5s
Explanation: The order of energy in subshells is based on the principal quantum number (n) and the angular momentum quantum number (l).
Correct answer: 5s > 3d > 4s > 3p