Answer:
The total energy of the photons detected in one hour is 7.04*10⁻¹¹ J
Explanation:
The energy carried by electromagnetic radiation is displaced by waves. This energy is not continuous, but is transmitted grouped into small "quanta" of energy called photons. The energy (E) carried by electromagnetic radiation can be measured in Joules (J). Frequency (ν or f) is the number of times a wave oscillates in one second and is measured in cycles / second or hertz (Hz). The frequency is directly proportional to the energy carried by a radiation, according to the equation: E = h.f, (where h is the Planck constant = 6.63 · 10⁻³⁴ J / s).
Wavelength is the minimum distance between two successive points on the wave that are in the same state of vibration. it is expressed in units of length (m). In light and other electromagnetic waves that propagate at the speed of light (c), the frequency would be equal to the speed of light (≈ 3 × 10⁸ m / s) between the wavelength :

So:

In this case, the wavelength is 3.35mm=3.35*10⁻³m and the energy per photon is:

E=5.93*10⁻²³ 
The detector is capturing 3.3*10⁸ photons per second. So, in 1 hour:

E=7.04*10⁻¹¹ 
The total energy of the photons detected in one hour is 7.04*10⁻¹¹ J
The answer is: the mass of 6.02 x 1023 representative particles of the element.
The base SI unit for molar mass is kg/mol, but chemist more use g/mol (gram per mole).
For example, molar mas of ammonia is 17.031 g/mol.
M(NH₃) = Ar(N) + 3 · Ar(H) · g/mol.
M(NH₃) = 14.007 + 3 · 1.008 · g/mol.
M(NH₃) = 17.031 g/mol.
The molar mass (M) is the mass of a given substance (in this example ammonia) divided by the amount of substance.
B- 90 grams bc 45 mL times 2 equals 90
Fluorine 20 (F - Atomic number 9 and atomic mass 20). Firstly we need to know what is beta decay. Beta decay occurs when one neutron changes into a proton and an electron therefore the atomic mass will remain the same as even though we loose a neutron it is replaced by a proton, the atomic number is always raised by 1 when one beta decay occurs. The produced electron is shot out of the nucleus at an incredible speed. This speedy electron we call a beta particle.
Ok now the reaction.
20 20 0
F -> Ne + e
9 10 -1
Remember the atomic number determines the nature of the element ( i.e what elemnt it is).
Hope this helps :).