Question

Short-wavelength UV is sometimes called vacuum UV, because it is strongly absorbed by air and must be studied in a vacuum. Calculate the photon energy in eV for 100-nm vacuum UV, and estimate the number of molecules it could ionize or break apart.

Answer 1

Energy of photon, E = 12.43 eV

Step-by-step explanation:

It is given that,

Wavelength of UV vacuum,
`\lambda=100\ nm=10^(-7)\ m`

Energy of photon is given by :

`E=(hc)/(\lambda)`

h = Planck's constant

c = speed of light

`E=(6.64* 10^(-34)* 3* 10^8)/(10^(-7))`

`E=1.99* 10^(-18)\ J`

or

`E=(1.99* 10^(-18))/(1.6* 10^(-19))\ eV`

E = 12.43 eV

So, the energy of the photon is 12.43 eV. Hence, this is the required solution.