Calculate the energy of a photon emitted when an electron in a hydrogen atom undergoes a transition from n=7 to n=1

Answer : The energy of photon =

Solution : Given,

Final energy level = 1

Initial energy level = 7

Formula used :

   ..........(1)

where,

= wavelength

R = Rydberg's constant = 1.0974

= final energy level

= initial energy level

Now put all the given values in above formula (1), we get the value of wavelength.

=  

Now we have to calculate the energy of photon by using formula,

where,

E = energy

h = planck's constant =

c = speed of light =

= wavelength

put all the values in this formula, we get the energy of photon.

=

the answer is   c.) 1575 j.

explanation:

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"