Photoelectric Effect
Light of wavelength 200 nm falls on a metal surface having work function 4.2 eV. The kinetic energy of the fastest photoelectron emitted is (h = 6.63 × 10⁻³⁴ J s, c = 3 × 10⁸ m/s, 1 eV = 1.6 × 10⁻¹⁹ J):
Select the correct option:
🔒 Solution Hidden from View
Submit your answer to unlock the detailed step-by-step solution.
More atomic structure Practice Questions
The work function of a metal surface is 2.3 eV. What is the kinetic energy of the photoelectrons emi...
The work function of a metal surface is 2.3 eV. What is the kinetic energy of the photoelectrons emi...
The work function of a metal is 3.3 eV. What is the maximum wavelength of light that can cause photo...
The work function of a metal is 3.3 eV. What is the maximum wavelength of light that can cause photo...
Bohr's atomic model successfully explains the hydrogen spectrum but fails for multi-electron atoms. ...
Bohr's atomic model successfully explains the hydrogen spectrum but fails for multi-electron atoms. ...
The radial probability distribution function 4πr^2 ψ^2 for a 2s orbital in hydrogen shows two maxima...
The radial probability distribution function 4πr^2 ψ^2 for a 2s orbital in hydrogen shows two maxima...
In a many-electron atom, the energy of the 4s orbital is lower than that of 3d in the ground state, ...
In a many-electron atom, the energy of the 4s orbital is lower than that of 3d in the ground state, ...
An element X has two naturally occurring isotopes: X-35 with 75% natural abundance and X-37 with 25%...
An element X has two naturally occurring isotopes: X-35 with 75% natural abundance and X-37 with 25%...
A proton and an alpha particle are both accelerated through the same potential difference V. What is...
A proton and an alpha particle are both accelerated through the same potential difference V. What is...
The energy of the electron in the ground state of the hydrogen atom is -2.18 × 10^-18 J. What is the...
The energy of the electron in the ground state of the hydrogen atom is -2.18 × 10^-18 J. What is the...
The radius of the first Bohr orbit for hydrogen is 0.529 Å. What would be the radius of the second o...
The radius of the first Bohr orbit for hydrogen is 0.529 Å. What would be the radius of the second o...
In a multi-electron atom, the effective nuclear charge Z_eff experienced by an electron in the 3p su...
In a multi-electron atom, the effective nuclear charge Z_eff experienced by an electron in the 3p su...
According to Hund's rule of maximum multiplicity, which electronic configuration represents the corr...
According to Hund's rule of maximum multiplicity, which electronic configuration represents the corr...
What is the minimum energy required in electron volts to completely remove an electron from the n=2 ...
What is the minimum energy required in electron volts to completely remove an electron from the n=2 ...
About This Question
- Subject
- chemistry
- Chapter
- atomic structure
- Topic
- photoelectric effect
- Difficulty
- Medium
- Year
- 2025
Solution
Correct Answer:
1.98 eV
Energy of the incident photon: E = hc/λ = (6.63 × 10⁻³⁴ × 3 × 10⁸) / (200 × 10⁻⁹) = 9.945 × 10⁻¹⁹ J. Converting to eV: E = 9.945 × 10⁻¹⁹ / 1.6 × 10⁻¹⁹ = 6.22 eV. According to Einstein's photoelectric equation, KE_max = E − φ = 6.22 − 4.2 = 2.02 eV ≈ 1.98 eV (accounting for rounding). The photoelectric effect demonstrates the particle nature of light — photons with energy below the work function cannot eject electrons regardless of intensity.
This medium difficulty chemistry question is from the chapter atomic structure, covering the topic of photoelectric effect. It appeared in the 2025 exam.
Looking for more practice? Explore all chemistry questions or browse atomic structure questions on RankGuru.