Free Atomic Spectra MCQs with Answers

• A. Electrically neutral
• B. Positively charged
• C. Negatively charged
• D. None of above

Explanation: (a) Electrically neutral: This option is not correct. Rutherford's experiment showed that the central part of an atom, called the nucleus…

• A. Neil Bohr
• B. Einstein
• C. Compton
• D. Rutherford

Explanation: The first theory about the structure of an atom was introduced by:(a) Neil Bohr: Neil Bohr, also known as Niels Bohr, proposed the Bohr…

• A. Rydberg rays
• B. Roentgen rays
• C. Ultraviolet rays
• D. Zig-zag rays
• E. Ruby rays

Explanation: The correct answer is Roentgen rays. X-rays were discovered by Wilhelm Conrad Roentgen in 1895, and in honour of his discovery, they are…

• A. Neon
• B. Hydrogen
• C. Carbon dioxide
• D. Sulphur dioxide

Explanation: Atomic spectra are the spectra of frequencies of electromagnetic waves emitted or absorbed during transitions of electrons between energy…

• A. 1,000 V is maintained
• B. 10,000 V is maintained
• C. 25,000 V is maintained
• D. 50,000 V is maintained

Explanation: During the production of X-rays, a high voltage is applied between the cathode and anode in an X-ray tube, but 50000V is commonly used.

• A. 2 to 3
• B. 3 to 2
• C. 5 to 4
• D. 6 to 2

Explanation: The longest wavelength in the Balmer series will be emitted when the electron transitions from the 3rd orbital to the 2nd orbital.

• A. Cathode rays
• B. Canal rays
• C. Gamma rays
• D. Beta rays

Explanation: Option A: Cathode rays are streams of electrons that are emitted from a cathode, which is a negatively charged electrode.

• A. Speed of sound
• B. Speed of electron
• C. Speed of alpha - particles
• D. Speed of light and gamma rays

Explanation: Option A: The speed of sound is the speed at which sound waves travel through a medium.

• A. Electric field only
• B. Magnetic field only
• C. Electric and magnetic field
• D. None of these

Explanation: X-rays are a form of electromagnetic radiation, meaning they are uncharged and cannot be influenced by electric or magnetic fields.

• A. Decrease in velocity
• B. Increase in frequency
• C. Increase in velocity
• D. Decrease in their intensity

Explanation: Option A: The velocity of an X-ray is not directly related to its penetrating power.

• A. 1/λ=Rh(1/22 - 1/n2); n=3,4,5
• B. 1/λ=Rh(1/42 - 1/n2); n=2,3,4,5
• C. 1/λ=Rh(1/42 - 1/n2); n=5,6,7
• D. 1/λ=Rh(1/32 - 1/n2); n=4,5,6

Explanation: The correct formula for the Paschen series is Option D: 1/λ=Rh(1/32 - 1/n2); n=4,5,6.

• A. -2.51 eV
• B. -3.50 eV
• C. -13.6 eV
• D. -0.85 eV

Explanation: The energy of the nth energy level in hydrogenE = -R(1/n²) and R = 2.18x10-18 J Rydberg constant in JoulesE = -2.18x10-18 J (1 / 4²)E =…

• A. 13.6 V
• B. 136.0 V
• C. 3.4 V
• D. None of these options are correct

Explanation: Ionisation energy (IE) is the minimum energy needed to remove the outermost (valence) electron from an isolated, gaseous atom or molecule…

• A. n=3
• B. n=2
• C. n=4
• D. n=5

Explanation: In the Brackett series, the electrons are transited from n>4 orbits, so that naturally means option D is the correct option.

• A. 2
• B. 1
• C. 4
• D. 0.05

Explanation: Option C is correct. The following is the correct solution:

• A. 0.5
• B. 2
• C. 1
• D. 4

Explanation: The correct option is 4. The following is the correct solution:

• A. Charged pattern
• B. Fingerprint pattern
• C. Discharged pattern
• D. None of these options is correct

Explanation: Option B correctly states that spectral lines are like a "fingerprint pattern" of absorbed or emission energy in a spectrum.

• A. 1.89 eV
• B. 2.9 eV
• C. 5.6 eV
• D. 7.8 eV

Explanation: Students should learn that the longest wavelength in the Balmer series is 656 nm.

• A. Band spectra
• B. Line spectra
• C. Emission spectra
• D. Absorption spectra

Explanation: Line spectra consist of discrete and distinct lines of colours or wavelengths.

• A. Ultraviolet
• B. Infrared
• C. Visible
• D. None of these

Explanation: The light we see is called visible light, a form of electromagnetic radiation.