Final answer:
The energy of the third energy level (n=3) of a hydrogen atom can be calculated using E = -13.6 eV/n². Converting this energy to joules requires using the conversion factor 1 eV = 1.602 x 10^-19 J. The energy in joules for the third energy level is approximately -2.42 x 10^-19 J.
Step-by-step explanation:
The energy of an electron in the third energy level (n=3) of a hydrogen atom can be calculated using the equation E = -13.6 eV/n². To convert this energy to joules, we need to use the conversion factor 1 eV = 1.602 x 10^-19 J. Plugging in the value of n=3, we get:
a) E = -13.6 eV/3² = -13.6 eV/9 ≈ -1.51 eV
To convert this to joules: -1.51 eV * 1.602 x 10^-19 J/eV ≈ -2.42 x 10^-19 J