What is wavelength of light if the energy of one photon is 2.925 × 10-19 J? (h =

To find the wavelength of light corresponding to an energy of 2.925 × 10⁻¹⁹ J, we can use the relationship between energy and frequency:

Calculate the frequency of the photon using the formula: [ f = \frac{E}{h} ] where:
(E) is the energy of the photon (given as (2.925 × 10⁻¹⁹ , \text{J}))
(h) is Planck’s constant ((6.63 × 10⁻³⁴ , \text{J} \cdot \text{Hz}^{-1}))
Substituting the given values: [ f = \frac{2.925 × 10⁻¹⁹ , \text{J}}{6.63 × 10⁻³⁴ , \text{J} \cdot \text{Hz}^{-1}} ] Calculating the frequency: [ f \approx 4.41 × 10^{14} , \text{Hz} ]

Now, we can find the wavelength using the speed of light ((c)): [ c = f \cdot \lambda ] Rearranging for wavelength: [ \lambda = \frac{c}{f} ] Substituting the known values: [ \lambda = \frac{3.00 × 10^8 , \text{m/s}}{4.41 × 10^{14} , \text{Hz}} ] Calculating the wavelength: [ \lambda \approx 6.80 × 10^{-7} , \text{m} ]
Therefore, the wavelength of light corresponding to an energy of (2.925 × 10⁻¹⁹ , \text{J}) is approximately 680 nm (option A).