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 35 of 47
- A. 1,0,0, 1/2
- B. 2,1,0,2,+1/2
- C. 2,0,0,-1/2
- D. 1,1,1, +1/2
Explanation: Be has the electronic configuration : 1s2,2s2 ,the fourth electron is present in 2nd shell so principle quantum number (n)=2,the fourth…
Correct answer: 2,0,0,-1/2- A. High
- B. Zero
- C. Low
- D. Negligible
Explanation: The electron density between the s and 2s orbitals is zero as the region is a node(the region where the probability of finding an electron…
Correct answer: Zero- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The angular momentum of the electron is given by : nh/2pie where n=1,2,3...etc. and in option 'B' n=2,hence it is the correct option.
Correct answer: Option B- A. Increase
- B. Remain constant
- C. Decrease
- D. vary inversely to the frequency
Explanation: Wavelength and wave numbers are inversely proportional to each other.
Correct answer: Decrease685. The sets of numerical values which give acceptable solutions for electron of any atom is called:
- A. Principal quantum no.
- B. Magnetic quantum no.
- C. Azimuthal quantum no.
- D. Quantum no.
Explanation: Quantum numbers are the set of four values used to describe the unique properties of electrons and there behaviour within an atom.
Correct answer: Quantum no.- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The total energy of an electron in the nth orbit of a hydrogen atom is given by the formula En = -13.6 eV/n2.
Correct answer: Option D- A. 9/16a0
- B. 3a0
- C. 1.5a0
- D. 4a0
Explanation: Step 1: Bohr's radius formulaFor the nth orbit of a hydrogen-like ion:rₙ = (n² × a₀) / ZWhere:n = orbit number (principal quantum…
Correct answer: 9/16a0- A. x/9
- B. x/3
- C. x
- D. 9x
Explanation: Bohr's Model and Velocity:According to Bohr's model, the velocity of an electron in the nth orbit is inversely proportional to the orbit…
Correct answer: x/3- A. 16πx
- B. 8πx
- C. 4πx
- D. None of these
Explanation: Bohr's Quantization of Angular Momentum:According to Bohr's model, the angular momentum of an electron in an orbit is quantized:mvr=n2πh…
Correct answer: 16πx- A. Z=2
- B. Z=3
- C. Z=4
- D. Z=5
Explanation: Part 1: Minimum Energy DifferenceEnergy of an X-ray Photon:The energy of a photon is related to its wavelength by the equation:E=λhc…
Correct answer: Z=2- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: This option is correct.Spin angular momentum =√S(S+1)h2π=√12(12+1)h2π=√3h4π
Correct answer: Option A- A. 7 or 8
- B. 11 or 12
- C. 5 or 6
- D. 10 or 11
Explanation: The total number of electrons in copper (Cu), which has an atomic number of 29, is 29. The electron configuration is [Ar] 3d10 4s1.
Correct answer: 11 or 12- A. 1.71 x 10^21
- B. 1.71 x 10^30
- C. 6.02 x 10^23
- D. 2.85 x 10^26
Explanation: Convert the power to watts:The transmitter's power is given as 1 kW, which is equal to 1000 watts (W). 2.
Correct answer: 1.71 x 10^30- A. 3R
- B. 5R/9
- C. 3R/4
- D. 8R/9
Explanation: Recall the Rydberg Formula and Our ValuesWe know the Rydberg formula: νˉ=RZ2(1/n12 −1/n22 ) We found:Z (for He+) = 2n2 (initial level) =…
Correct answer: 5R/9- A. 1:4
- B. 1:2
- C. 2:1
- D. 3:2
Explanation: When the frequency of incident radiation changes from 2fo to 5fo, the maximum velocity of emitted electrons changes in an inverse…
Correct answer: 1:2- A. 3
- B. 6
- C. 9
- D. 12
Explanation: De Broglie's Hypothesis:De Broglie proposed that electrons have wave-like properties.In Bohr's model, the electron's wave must form a…
Correct answer: 3- A. 3
- B. 6
- C. 9
- D. 12
Explanation: The number of waves in the third Bohr's orbit of hydrogen will be 3.The third Bohr's orbit of hydrogen has a principal quantum number of…
Correct answer: 3- A. high
- B. zero
- C. low
- D. negligible
Explanation: The electron density between the s and 2s orbitals is zero. In an atom, electrons occupy specific energy levels and orbitals.
Correct answer: zero- A. KO2 , NO 2
- B. K2O2 , KO2
- C. K2O, NO2
- D. NO2 , N2O2
Explanation: In KO2, O-2 → (superoxide) has one unpaired electron and NO2also has one unpaired electron. Thus, KO2 and NO2 are paramagnetic.
Correct answer: KO2 , NO 2- A. Addition of electron pair
- B. Mixing of atomic orbitals
- C. Removal of electrons
- D. Separation of orbitals
Explanation: Hybridization is mixing up of orbitals of nearly same energy giving rise to the formation of entirely new orbitals (hybridized orbitals)…
Correct answer: Mixing of atomic orbitals