JEE Mains · Chemistry · STD 11 - 2. structure of atom
The surface of sodium metal is irradiated with radiation of wavelength \(x\) nm. The kinetic energy of ejected electrons is \(2.8 \times 10^{-20}\) J. The work function of sodium is \(2.3\) eV. The value of \(x\) is _____ \(\times 10^2\) nm. (Nearest integer)
(Given: \(h = 6.6 \times 10^{-34}\) J s; \(1\) eV \(= 1.6 \times 10^{-19}\) J; \(c = 3.0 \times 10^8\) m s\(^{-1}\))
- A 5
- B 10
- C 15
- D 20
Answer & Solution
Correct Answer
(A) 5
Step-by-step Solution
Detailed explanation
The work function of sodium in Joules is: \(\Phi = 2.3 \times 1.6 \times 10^{-19} = 3.68 \times 10^{-19}\) J The kinetic energy of the ejected electrons is: \(K = 2.8 \times 10^{-20} = 0.28 \times 10^{-19}\) J Using the photoelectric equation, the energy of the incident photon…
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