6. what is the wavelength of a photon that has an energy of 2.52 x 10^(-19) j? identify the type of…

6. what is the wavelength of a photon that has an energy of 2.52 x 10^(-19) j? identify the type of radiation. 7. a photon of light has an energy of 3.82 x 10^(-13) j. calculate the frequency & identify the type of radiation.
Answer
Explanation:
Step1: Recall energy - wavelength formula
The energy of a photon is given by $E = h\frac{c}{\lambda}$, where $E$ is energy, $h = 6.626\times10^{-34}\ J\cdot s$ (Planck's constant), $c= 3.0\times 10^{8}\ m/s$ (speed of light) and $\lambda$ is wavelength. We can re - arrange it to solve for $\lambda$: $\lambda=\frac{hc}{E}$.
Step2: Substitute values for first question
For $E = 2.52\times 10^{-19}\ J$, $h = 6.626\times10^{-34}\ J\cdot s$ and $c = 3.0\times 10^{8}\ m/s$. $\lambda=\frac{(6.626\times 10^{-34}\ J\cdot s)\times(3.0\times 10^{8}\ m/s)}{2.52\times 10^{-19}\ J}$ $\lambda=\frac{19.878\times 10^{-26}\ J\cdot m}{2.52\times 10^{-19}\ J}=7.89\times 10^{-7}\ m = 789\ nm$. This is in the visible light region (400 - 700 nm is visible, but near - infrared starts around 700 nm, so it's near - infrared).
Step3: Recall energy - frequency formula for second question
The energy of a photon is also given by $E = h\nu$, where $\nu$ is frequency. We can solve for $\nu$: $\nu=\frac{E}{h}$.
Step4: Substitute values for second question
For $E = 3.82\times 10^{-13}\ J$ and $h = 6.626\times10^{-34}\ J\cdot s$. $\nu=\frac{3.82\times 10^{-13}\ J}{6.626\times10^{-34}\ J\cdot s}=5.76\times 10^{20}\ Hz$. This is in the gamma - ray region (frequencies above $10^{19}\ Hz$ are gamma - rays).
Answer:
- Wavelength for first photon: $789\ nm$, type of radiation: near - infrared
- Frequency for second photon: $5.76\times 10^{20}\ Hz$, type of radiation: gamma - ray